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Graham Rice on Trials

Updates on trials and awards from the Royal Horticultural Society by Graham Rice

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  • Hosta ‘Sara’s Sensation’: New from Bali-Hai Nursery

    Graham Rice on 21 May 2010 at 07:56 PM

    Hosta,Sara's Sensation,Bali-Hai,Paul and Linda Hofer. Image: Bali-Hai Nursery.‘Frances Williams’ is one of our most popular hostas. Basically it’s like Hosta sieboldiana ‘Elegans’ but with a gold edge to the leaf and indeed it is thought to be a sport of ‘Elegans’. ‘Frances Williams’ itself has produced a number of sports and this new introduction, ‘Sara’s Sensation’, looks to be one of the best.

    ‘Sara’s Sensation’ is an altogether brighter plant with a much broader gold border and smaller blue-green centre – in effect each leaf is gold with a central blue-green flash. Its rounded leaves are very thick and corrugated indeed it’s thought to be a tetraploid – that is, with twice the normal number of chromosomes – which helps create this extra substance. With such thick leaves it’s likely to be slug resistant. It will slowly but steadily make a plant about 50cm/20in high and 1.2m/4ft across and make a fine specimen in shady borders. In early summer almost pure white flowers appear on short stems.

    ‘Sara’s Sensation’ has been around for some time, it was registered with the American Hosta Society back in 1998, but is only now available here in Britain for the first time. It was found as sport of ‘Frances Williams’ by Paul and Linda Hofer from Ohio, Paul also discovered one of the finest hostas of all, the gold-centred ‘Paul’s Glory’ which was Hosta of the Year in 1999.

    You can order Hosta ‘Sara’s Sensation’ from Bali-Hai Nursery.


  • Improved trials and awards coverage

    Graham Rice on 18 May 2010 at 01:46 PM

    Verbena trial at Wisley. Image: Ali Cundy, RHS Trials OfficeWell, I’m pleased to say that the RHS has been upgrading its coverage of plant trials and plant awards here on the website. Naturally, this means change and one of the changes is that this blog is disappearing – this is my last post. But I’m glad to say that it’s being replaced by two new features.

    So starting today, every month I’ll be bringing you news of one of the plants which has recently been given an Award of Garden Merit. I start with the lovely fragrant pink Dianthus Candy Floss ('Devon Flavia’) (below right, click to enlarge) which gained its award after last year’s trial at Wisley. Look for my piece on the Latest AGM Plants around this time every month.Dianthus Candy Floss ('Devon Flavia’). Image: Caroline Beck, RHS.

    I’m also starting a second new series, featuring a seasonal choice of ten Award of Garden Merit plants. Every month I’ll pick a seasonal theme – the first will be a choice of plants for containers – and select ten appropriate plants which have received an Award of Garden Merit. Look for this around the beginning of each month.

    And there’s plenty more happening on the new upgraded Plant Trials and Awards pages.
    Find out how plants qualify for an AGM
    Download lists of AGM plants
    Search for AGM plants
    Find out about the plant trials which help decide which plants receive an AGM
    Check out which plants are currently being trialed
    Download free full colour bulletins on important plant trials
    Look over all my previous posts about trials and awards
    And start here for news of events - like next month’s Pink and Carnations Open Day - awards and everything else about plant trials and awards.

    So thanks for following this blog, and for your comments here and also your many comments by email. My RHS New Plants blog continues. Be sure to hop over to the enhanced Plant Trials and Awards pages where my coverage starts today.


  • Irises with colourful new foliage

    Graham Rice on 05 May 2010 at 08:01 PM

    Iris pseudata ‘Kinshizen’ Image: © All rights reserved.Down on the Wisley trials field is a small trial of water irises, plants derived from Iris ensata, I. pseudacorus, I. sibirica, I. versicolor and I. virginica. When I looked them over a couple of weeks ago they were a long way from flowering but some revealed a totally different feature, one that could bring colour to a moist and sunny border long before the flowers open: the new foliage. These new leaves are coloured in one of two ways, they emerge yellow and fade to green or are boldly stained purple at the base.

    A hybrid of I. ensata and I. pseudacorus, I. x pseudata ‘Kinshizen’ (above, click to enlarge) was the best of those with yellow in the young leaves; it was very bright. The plants are clearly vigorous, and the colour appears to last well. The flowers look to be pale apricot shading to magenta purple around a yellow throat.

    An unnamed seedling, number 32 in the trial, was more brightly coloured at first but turned to green more quickly and its impact was lost. The colour of ‘Holden’s Child’ was closer to pale green and dark green rather than yellow and green. The flowers will be purple-blue with a gold throat.

    I. x
 robusta ‘Dark Aura’ Image: © All rights reserved.Amongst those with purple staining at the base of the leaves, I. x robusta ‘Dark Aura’ (left, click to enlarge) stood out. A hybrid between I. versicolor and I. virginica it’s vigorous, and the new shoots are a vivid plum shade with almost no green; its flowers will be purple-blue and held on unusually black stems. ‘Tango Music’ was similar but significantly less vigorous. ‘Mainstream Tempest’ was also good, though the foliage was noticeably shorter and the colouring more red than purple. The flowers of both will be two-tone purple. Both are hybrids between I. sibirica and I. versicolor.

    So the pick for early foliage colour were I. x pseudata ‘Kinshizen’ for yellow colouring and I. x robusta ‘Dark Aura’, which already has an AGM, for purple colouring. Both add new accents of colour to early season damp gardens. Be sure to take a look at them later in the season when they're in bloom.


  • New flowering currant trial

    Graham Rice on 28 Apr 2010 at 01:28 PM

    Ribes sanguinem,'Tydeman's White',flowering currant, Wisley, RHS. Image: © Do not reproduce in any way without permission.On one of my visits to the Wisley trials field last week I noticed that the new trial of flowering currants, Ribes sanguineum, had been planted. And, it being spring, they were all in flower. And some of them were already impressive. This ability to look good so soon after planting is a great virtue in small gardens; when you put in a new plant it’s a great bonus if it makes an impact straight away.

    The three that were most impressive, at this very early stage of the trial, were three of the less familiar varieties – and they covered the full spectrum of colour. So often we see only ‘Pulborough Scarlet’ or ‘King Edward VII’ and it was refreshing to see so many others.

    Perhaps the most striking on this occasion was ‘Tydeman’s White’. A lovely pure white, with just a little pink in the calyces, the flower clusters are well packed, they’re carried at every leaf joint, and arch downward elegantly to make a very attractive plant.

    In a vivid pink shade was R. sanguineum ‘Koja’. One of the striking features of ‘Koja’, apart from the slightly cerise pink flower colour, was the fact that rather than arching fully downward the flower clusters tended to be held at a higher angle, farther away from the stems. So there was little chance of the foliage masking the display.

    And finally the most strongly coloured of all, in a deep bright red, was ‘Red Pimpernel’. Rather upright in habit and with dark stems and a white eye to the flowers, ‘Red Pimpernel’ was also very prolific.

    You’ll notice in the background of the picture that the soil is completely covered with landscape fabric. This serves two main purposes. It keeps weeds under control; weeding can be a huge task on such a large area so it saves time and allows the staff to give their attention to tasks which really need their skills. And secondly it helps conserve moisture.

    Of course, it’s early days. Check back next April; after a year of growth it should be quite a spectacle.


  • Flowering bergenias

    Graham Rice on 26 Apr 2010 at 06:21 PM

    When I was at the RHS Garden at Wisley the other day, most of the bergenias from the recent trial were still in place and were flowering away merrily. It was good to see how prolific some of them are. Three in particular caught my eye, all very different and all with less common species blood.

    Bergenia stracheyi, Alba Group,winter perennial,winter flowers, Image: © Do not reproduce in any way without permission. Read More...

  • Daffodils on trial at Wisley

    Graham Rice on 18 Apr 2010 at 10:30 AM

    In my last post I looked at the display of daffodils which already have the Award of Garden Merit. But there are also some superb plants in the Wisley trial itself. Planted last autumn, this is their first year in flower.

    The first one I noticed was ‘Rip van Winkle’. This a very old double flowered daffodil whose flower is made up of a mass of slender petals. The problem is – the heads are too heavy for the stems. The stems arch over so the flowers almost touch the ground. In soil that was less rich the stems may be shorter and less weak but they did not look tempting.Narcissus 'Stann Creek',daffodil,AGM Image: © Do not reproduce in any way without permission.

    But the ones I especially liked were ‘Stann Creek’ and ‘Saint Victor’, not least because in their first year they both produced two flowers from each bulb.

    ‘Stann Creek’ (above, click to enlarge) is both stylish and dramatic. This lemon-and-lime variety has very large flowers, in the traditional trumpet style but in a very unusual and effective colouring. Most of the trumpet and the base of the petals is white, the tip of the trumpet and much of the petal colouring is lemon-and-lime yellow. There were one or two off-types in the planting but the overall effect was delightful.

    The other one I especially liked was ‘Saint Victor’ (below, click to  enlarge). This is a traditional yellow daffodil, so what makes this more impressive than good old ‘Golden Harvest’? First of all the flowers are enormous, and they’re held on stout stems so the Narcissus 'Saint Victor',daffodil,AGM Image: © Do not reproduce in any way without permission.stems don’t collapse under their weight. Secondly the deep yellow flowers are a wonderful rich colour with the flared trumpet slightly darker than the petals. Finally, the flowers face outward so we get the best of the display.

    The display of these candidates for the Award of Garden Merit continues on the trials field at Wisley through this lovely sunny weather so make the most of them and note those that would look good in your own garden. There’s nothing to compare with seeing so many all growing side by side.


  • AGM Narcissus at Wisley

    Graham Rice on 13 Apr 2010 at 03:54 PM

    Narcissus 'Intrigue',daffodil,AGM Image: © Do not reproduce in any way without permission.All over the country the daffodils are at their peak – and Wisley is no exception. You’ll see the displays almost as soon as you get there. But make your way to the trials field and you’ll find a rather special display. Every one of the daffodils which have been given an Award of Garden Merit after being trialed at Wisley. It’s a great opportunity to choose your favourites from amongst those already chosen as the best of the best. So that’s what I did yesterday. Three stood out. Two of those that I especially liked were more subtle types, and one was more bold and traditional.

    ‘Intrigue’ (above, click to enlarge) is very unusual. It’s a yellow and white bicolour in a unique pattern, both cup and petals are bicoloured. The cup of each flower is white at the tip and lemon yellow at the base, while the petals are the reverse – white at the centre and yellow at the tips. It’s gorgeous. And with three flowers on each stem the display is both stylish and colourful.Narcissus 'Reggae',daffodil,AGM Image: © Do not reproduce in any way without permission.

    Another that I especially liked was ‘Reggae’ (left, click to enlarge). I’m not sure quite how the name relates to the flower, but this is a very neat, and short, cyclamineus hybrid. The cup is pale salmon, the petals are slightly swept back and white. The result is a very appealing group.

    Finally, I was also struck by a more traditional daffodil. ‘Goldfinger’ was the traditional yellow trumpet daffodil (a ‘King Alfred’ type, if you like) with a very dramatic impact. Both trumpet and petals are vivid yellow but, unlike the flowers of the similar ‘Arkle’, the flowers aged well; in ‘Arkle’, the tips of the trumpets turned papery as they aged. ‘Goldfinger’ aged more gracefully.

    There are masses more AGM daffodils to see. Although some are over, some are only just starting to open. Well worth a look. And you can see the whole list on the RHS website.


  • AGM for 'Scrumptious' apple

    Graham Rice on 31 Mar 2010 at 01:28 PM

    Apple,Scrumptious,Hugh Ermen,AGM,Award of Garden Merit,RHS,Wisley. Image ©Orange PippinFor the first time in over ten years an apple has been given the Award of Garden Merit. Not since 1998 has an apple received the award, and it’s gone to the very aptly named ‘Scrumptious’.

    ‘Scrumptious’ is an early apple, for eating straight from the tree in mid August and September. Introduced back in 1980, it has been grown and sampled at Wisley for many years – evidence of the rigorous assessment that apples undergo.

    With its bright red skin it looks gorgeous and its crisp flesh has a lovely flavour - aromatic, sweet but not sugary, with a few hints of strawberry. It also has a number of other valuable features.

    * It’s self fertile. So although it will produce the heaviest crop if pollinated by another variety it will also bring a very respectable crop if grown without. It is, however, a good pollinator of other apples.
    * It’s relatively thin-skinned so great for kids.
    * It fruits well on young treesApple,Scrumptious,Hugh Ermen,AGM,Award of Garden Merit,RHS,Wisley. Image ©Orange Pippin
    * The flowers are more resistant to frost than those of many varieties, so it’s good for cold areas.
    * The fruit hangs on the tree, even after it’s passed its best.
    * ‘Scrumptious’ is a relatively disease-free variety.

    ‘Scrumptious’ is a cross between two favourites, ‘Golden Delicious’ and ‘Discovery’, raised by Hugh Ermen an apple enthusiast and apple breeder who raised a number of excellent eating and ornamental apples but who sadly passed away last autumn.

    You can find out more about the ‘Scrumptious’ apple on the Orange Pippin apple and orchards website.


  • Award winning raspberries

    Graham Rice on 27 Mar 2010 at 02:12 PM

    Raspberry,'Tulameen',AGM,Award of Garden Merit.  title=The number of gardeners growing fruit has rocketed in recent years and soft fruit, in particular, has become very popular. So the completion of a three year raspberry trial comes at a very timely moment. Coupled with the fact that raspberries are no longer only sold as bar root canes by mail order in the autumn but also now in spring as plants in large pots in garden centres, it’s time to take a look at the results of the trial.

    Sixteen summer varieties and eleven autumn fruiting varieties were grown. Just ten canes of each variety were planted so it was easy to see how a modest, garden-size planting would perform. Ten varieties were given an Award of Garden Merit – five for summer and five for autumn cropping. Six of the ten gained awards for the first time. It was also recommended that two varieties with existing AGMs have them removed.

    Raspberry,'Glen Ample',AGM,Award of Garden Merit.  title=The star of the whole trial, and a new award-winner, was 'Tulameen' (above, click to enlarge). Even early in the trials the judges said: “'Tulameen' has performed very well and appears to be much better than the rest. A good variety, with good flavour, pickability and weight of fruit.” The other new award went to ‘Glen Magna’ while ‘Glen Ample’ (left, click to enlarge), 'Malling Admiral' and 'Malling Jewel' were still up to AGM quality had their earlier awards re-confirmed.

    ‘Glen Ample’ was notable for producing 2kg of fruit per cane – in its first year, with 'Tulameen' close behind.

    Amongst the autumn-fruiting varieties ‘Autumn Bliss’ retained the AGM it’s had since 1993 and four new awards were made, to 'All Gold', 'Caroline', 'Joan J' and 'Polka'. With varieties from the summer group and from the autumn group, you can now look forward to a long season of top class, AGM raspberries. But not 'Glen Moy' and 'Glen Prosen', the judging panel decided that those two had had their day and others are now better.


  • What a plant needs to get an AGM

    Graham Rice on 23 Mar 2010 at 11:47 AM

    Hosta 'Sum and Substance',AGM,RHS,Award of Garden Merit, Image: © Do not reproduce in any way without permission.What is it that makes a good enough to deserve an AGM (Award of Garden Merit) from the Royal Horticultural Society? Well, with the busy Easter plant buying weekend approaching this seems like a good time to run a reminder of the features that a plant needs in order to be worthy of this high accolade. And, as you’ll see, a plant really must be good to qualify. And those that do qualify carry the AGM cup symbol (below). So let’s look at what the RHS requires.

    “It must be of outstanding excellence for ordinary garden decoration or use” The key phrase is “outstanding excellence”: whatever a plant’s ornamental or edible qualities may be, they must be of the highest standard.

    “It must be available” That is, if you can’t actually buy the plant it can’t receive the award. The RHS PlantFinder is often the best guide to availability, although the sources covered do not include seed companies. Awards to new plants may be held back until they appear in catalogues or garden centres but that’s the rule: if you can’t buy it can’t get an award.

    “It must be of good constitution” Plants must be fairly robust and resilient in normal growing conditions. Those which are weak do not qualify for the award.RHS AGM cup symbol,AGM,RHS,Award of Garden Merit, Image: ©RHS.

    “It must not require highly specialist growing conditions or care” The point here is that weekend gardeners with no special horticultural skills should be able to grow the plants in their own gardens without spending a huge amount of time and effort creating special conditions. Of course, plants have preferences - some like sun, some prefer shade; some require acid soil, some don’t. But other than these basic preferences, plants should not require special treatment.

    “It must not be particularly susceptible to any pest or disease” Speaks for
    itself, plants which are especially prone to pests and disease problems are not good garden plants and so do not qualify for the award.

    “It must not be subject to an unreasonable degree of reversion in its vegetative or floral characteristics” So, for example, variegated plants which repeatedly throw plain green shoots and double-flowered forms that regularly produce single flowers are not considered for an award.

    If all six of these requirements are met, then a plant deserves an Award of Garden Merit. At present 7,426 plants have received the award – so there’s plenty to choose from. Look out for the AGM cup symbol (above) on plant labels, in catalogues, in books and online.

    You can find out more about how plants are awarded the AGM on the AGM page on the RHS website.

    The RHS website also features lists of AGM plants.

    You can also search for AGM plants in different categories.


  • AGMs for endive

    Graham Rice on 10 Mar 2010 at 12:15 PM

    Endive trial,judges,AGM,Wisley. Image: ©RHSWith sowing season approaching, it’s time to take a look at last year’s Wisley trial of endive. This trial was also grown at the RHS gardens at Hyde Hall in Essex and Rosemoor in Devon.

    Endives may not be top of the list of salad crops or stir fry crops, but their texture and flavour make them invaluable. There are two types: curly or frisée endive has slender curly outer leaves, while escarole has broad leaves and is less bitter. Both types are traditionally blanched to reduce their bitterness.

    Both types were grown in the trial, sixteen varieties in all, and they were all sown both in April to crop in July, and again in June to crop in September. The first sowing received a ferocious battering from hail in early June but recovered promptly. Many of the plants from the April sowing ran to seed quite quickly, at all three sites, but while this would be a problem for commercial growers home gardeners could still harvest individual leaves. The other cultural issue was how to cover them for blanching.Endive 'Frenzy',AGM,Wisley,trial. Image: ©RHS

    The plants became too hot under black fleece, the easiest option, and tended to rot. Upturned plastic pots, secured by a cane through a drainage hole, were more successful. Upturned clay pots were better still but few home gardeners have access to enough sufficiently large clay pots. It was suggested that the plants could also be blanched simply by tying the leaves loosely together with twine. Visiting Joy Larkcom’s garden some years ago, I noticed that she blanched her endive using large upturned white dinner plates. It seemed to work well.

    Six varieties were given an Award of Garden Merit. The five frisée types to receive AGMs, with comments from the panel, were:
    ‘Despa’: “Heads are dense, but not hearting… Very little bolting.”
    ‘Frenzy’ (above, click to enlarge): “Heads are dense, but not hearting… grown for the high class restaurant trade.”
    ‘Kentucky’: “Intermediate frisée. Very productive, large heads. Blanches well.”
    ‘Plantation’: “Large frame, frisée type with broad leaves and very thin petioles (leaf stems). Very little tip-burn.”
    ‘Wallone’: “Vigorous, large-framed frisée type. Stands well.”

    The one escarole type to receive the AGM was ‘Natacha’: “Heads are quite loose and non-hearting. Attractive escarole type. Not bolting. Strong flavour. Not prone to tip-burn.”

    It’s also worth noting that it was voted to remove the AGM given to ‘Glory’ in 2002 as it suffered badly from tip-burn and had been superseded.

    Sources of seed vary from season, check the Royal Horticultural Society's leaflet Award of Garden Merit Vegetables, currently being updated, for stockists.
    This leaflet is available online.


  • Crocus trial flowering at last

    Graham Rice on 02 Mar 2010 at 01:15 PM

    This winter’s weather has delayed flowering of the Crocus trial down on the Portsmouth Field. The first two visits by the assessment panel were cancelled because after all that snow there were so few in flower.

    Crocus 'Snow Bunting',RHS,Wisley,trial. Image: ©Meneerke bloom, used under the terms of the GNU Free Documentation License Read More...

  • Gold Medal winners in Wisley/Fleuroselect trial

    Graham Rice on 25 Feb 2010 at 11:42 AM

    Sanvitalia speciosa 'Million Suns' - 2010 Fleuroselect Gold Medal. Image: ©FleuroselectThe vast array of trials held at the RHS Garden at Wisley is impressive in itself. But the RHS also participates in another trial, a pan-European trial to find the best new annual flowers.

    Fleuroselect has trial gardens in about thirty places across Europe in a wide range of climates and soil conditions. And one is at Wisley, not in the garden but at Deers Farm in Wisley village, the site of some of the Society's trials of shrubs and climbers. Deers Farm is only open on special open days, so look out for the opportunity to visit.

    In the Fleuroselect trial, new varieties are grown anonymously alongside the most similar existing variety and inspected by expert judges regularly through the growing season. The highest award is the Gold Medal and one interesting stipulation is that all Gold Medal winners must be made available to all other members of the Fleuroselect organisation - so Gold Medal winners have the potential quickly to become widely available from a range of suppliers.

    So what are the winners for this year, which did well both at the Wisley trial site and across Europe? There are three.Physostegia virginiana 'Crystal Peak White' - 2010 Fleuroselect Gold Medal. Image: ©Fleuroselect

    Sanvitalia speciosa 'Million Suns' (top, click to enlarge) combines three valuable features: it's colourful, compact and prolific. Ideal at the edge of containers or as neat ground cover at the front of a sunny border, 'Million Suns' needs little maintenance, rarely suffers from pests and diseases and will flower from May until the frosts. It branches well from the base and thrives in any sunny place in fertile soil that is not too soggy.

    Also winning a Gold Medal for this year is Physostegia virginiana 'Crystal Peak White' (right). This is a white flowered, seed-raised version of the familiar Obedient Plant with upright spikes densely packed with white flowers. The flowers drop off as they fade so there's no distraction from the clean look of the remaining flowers. Sow early, the plants will flower well in their first summer. Use them in containers in their first season, then move plants to the border in the autumn.

    Gaillardia x grandiflora 'Mesa Yellow' - 2010 Fleuroselect Gold Medal. Image: ©Fleuroselect Read More...

  • Smaller melons score well in a cloudy summer

    Graham Rice on 20 Feb 2010 at 12:20 PM

    Melon 'Emir',AGM,Wisley. Image: ©RHSSome gardeners are wary of growing melons. But last year’s trial of small-fruited varieties, grown outside, proved that they are not difficult – even in a relatively sunless summer. And these “single portion” melons are great for most households as each fruit is eaten fairly quickly so never gets the chance to spoil.

    Twenty varieties were grown, including some too new even to have a name, and seed was sown singly in 9cm pots at the end of April at 20-30C/68-80F. They were grown on at 20C/68F, potted into one litre pots and hardened off carefully from the end of May then planted out through black landscape fabric in mid June. The whole trial was covered in fleece to retain warmth until the plants flowered.

    It’s interesting to note that where the fruits rested on the landscape fabric some started to rot. The traditional practice of placing a tile or straw under each fruit to keep it off the round would have solved the problem.

    Melon 'Alvaro',AGM,Wisley. Image: ©RHS

  • AGMs for hardy chrysanths

    Graham Rice on 10 Feb 2010 at 01:59 PM

    Chrysanthemum 'Nell Gwynn',hardy,spray,chrysanthemum,AGM,Wisley. Image: ©GardenPhotos.comIn recent years, the Chrysanthemum trial at Wisley has been updated. And the way in which it’s been updated may seem surprising: more older varieties are being included. The reason for this is that the trial tended to focus on the latest varieties, but many older varieties of hardy garden chrysanths have become very popular, after a long period of relative neglect.

    So old Korean and Rubellum chrysanths are now being trialed and assessed, in particular, for how they perform grown naturally as hardy perennials for use in herbaceous and mixed borders - without the disbudding technique that exhibitors use. Newer varieties in this old style are also being included.

    Last year five of these hardy traditional varieties gained Awards of Garden Merit. Judy Barker, holder of the National Collection of  Korean, Rubellum and hardy spray chrysanthemums, is one of the assessment panel that judged these chrysanths, she told me about the hardiest of the AGM winners.

    ‘Aunt Millicent’ “Single flowers in very light pink fading to white, flowering in October forming a much branched dome. Found in an old garden in Kent.”

    ‘Carmine Blush’ “A lovely much branched dome of late flowering mauve-pink single flowers. A very tough plant giving a flush of weather resistant flowers at a time when most of the garden is finishing.”

    ‘Grandchild’ “Neat cushion of shocking pink double flowers flowering Sept-Oct. Imported from Minnesota in the 1980s.”

    ‘Nell Gwynn’ (top, click to enlarge) “The reason the committee liked this plant was the length of flowering time, from July-October. The single pink flowers tend to fade somewhat in strong sunshine but the colour deepens with lower temperatures. As it has a distinctive primrose yellow ring this could be picked up with companion planting.”Chrysanthemum 'Perry's Peach',hardy,spray,chrysanthemum,AGM,Wisley. Image: ©

     ‘Perry’s Peach’ (left, click to enlarge) “Single peachy flowers. Found in an old garden in Whitby in 1980 but without a name, so named by Perry’s Plants and sold from their nursery. They have it running around their border shrubs.”

    For more on these chrysanthemums, check out Judy Barker’s excellent National Collection website.


  • Sweet pea AGMs

    Graham Rice on 05 Feb 2010 at 09:27 AM

    Sweet pea 'John Gray', AGM, RHS, Wisley. Image ©Roger Parsons.The sweet pea trial at Wisley is always a big attraction to visitors – and the fragrance is often as powerful as the colour is enticing. But it’s not just an attractive display, it’s a serious trial with the expert sweet pea judges assessing the entries for both use in the garden and for exhibition.

    Just one new variety was considered of sufficiently high standard to be awarded an Award of Garden Merit this year - ‘John Gray’ (left, click top enlarge). Raised by Roger Parsons, holder of the National Collection of Sweet Peas, its large, boldly waved flowers are pale pink shading to white at the base.

    Roger told me about his new award-winning sweet pea: “'John Gray' is remarkable in being exceptionally good both for garden decoration and for cut flowers. Growth is vigorous and it flowers prolifically so that a clump of plants in the garden is covered in blooms. It has exceptionally large flowers and long stems for cutting.

    “Larger petals are generally more prone to weather damage,’ he added, “but 'John Gray' has good petal texture to resist this.”

    Named for the father of a Roger Parsons customer, who simply loved gardening, not only did ‘John Gray’ receive an AGM last year, but it also received an Award of Merit for Exhibition following the trial at Wisley in 2007.

    The panel of judges also assessed sweet peas given an AGM in earlier years to be sure that they continued to perform at AGM standard. For one variety, the news was not good. ‘Florencecourt’, given an AGM in 1997, was disappointing. Not only was there noticeable variation in the colour of the flowers on display but it was known that a completely incorrect variety was being sold under this name. So it was recommended that its AGM be withdrawn.Sweet pea 'Gwendoline', AGM, RHS, Wisley. Image ©Flower Seed World.

    Four other older varieties were also checked carefully but these were considered to still be of AGM standard. These were ‘Evening Glow’, the very popular ‘Gwendoline’ (left), 'Toby Robinson’ and ‘White Supreme’ – which gained its AGM as long ago as 1994.

    Seed of sweet pea ‘John Gray is available only from Roger Parsons.


  • Echinacea Fruity Doubles: New from Thompson & Morgan

    Graham Rice on 01 Feb 2010 at 10:31 PM

    Echinacea Coconut Lime, Pink Double Delight, Hot Papaya, Double Marmalade. Image ©Thompson & Morgan Seeds.In recent years there’s been a flood of new echinaceas, mainly from specialist breeders in North America and Europe. First it was all the new yellow and orange and red shades, now it’s double flowered varieties. Like the single flowered varieties, the first doubles that were available came in pink and white – now we have the ‘Fruity Doubles’ (click the picture to enlarge it).

    This collection is made up of four of the best varieties from master Dutch echinacea breeder Arie Blom. Specialising in double echinaceas propagated vegetatively so they’re all identical, and never from seed, these are so superior to the original double, ‘Razzmatazz’, which I found to be a poor plant. The colours are better, they don’t produce single flowers, and they support themselves much more effectively.

    This collection includes: ‘Coconut Lime’, white rays with a fluffy creamy lime cone; ‘Pink Double Delight’, in bright pink and like a more stable, self supporting version of ‘Razzmatazz’; and last year’s hot newcomer ‘Hot Papaya’, the first red double.

    Completing the collection is the latest of Arie Blom’s new doubles – ‘Double Marmalade’, a fiery orange double which is also available separately.

    Impressive in the garden and long lasting as cut flowers, give them plenty of sun and fertile soil which is well-drained in winter and they’ll thrive.

    You can order the Echinacea Fruity Doubles Collection of plants from Thompson & Morgan.

    You can also order Echinacea 'Double Marmalade', individually, from Thompson & Morgan and also from Mr Fothergill’s.


  • Abelias for flower and foliage

    Graham Rice on 29 Jan 2010 at 01:54 PM

    Abelia mosanensis Wisley, RHS, trial. Image © the last three years, there’s been a trial of Abelia varieties at Wisley’s Deer’s Farm. This is a valuable location in Wisley village which provides vital extra space for trials, and a number of important shrub trials have been grown there in recent years.

    The abelias have been grown there for the last five years and assessed regularly by the panel of shrub experts with the aim of choosing the very best to be given an Award of Garden Merit. It also proved a welcome opportunity to sort out some of the muddles in naming and this is still being completed.

    With so many variegated forms introduced in recent years, this prolonged regular assessment also provided a useful opportunity to check which varieties are stable and retain their variegation and which tend to revert to plain green. Full details will be provided in a Plant Bulletin, currently being prepared. I’ll let you know when it’s published.

    So which were the best?

    It was agreed that the rarely seen Abelia mosanensis (above, click to enlarge) was outstanding. It was the only one with red autumn foliage, it featured lovely sweetly scented flowers in spring and was also very hardy. It’s much more popular in America than here although the plant in the trial was propagated from a specimen already in the garden. It will be given a cultivar name in due course.

    Abelia x grandiflora 'Hopleys' variegated, Wisley, RHS, trial. Image © Do not reproduce without permission. Read More...

  • Weigelas, a mid term assessment

    Graham Rice on 20 Jan 2010 at 11:07 AM

    Weigela Monet (‘Verweig'), dwarf,variegated, My Monet, Wisley, RHS, trial. Image: ©ProvenWinners.comAt the far end of the Wisley Pinetum (come out of the restaurant, turn right, keep going) is the trials area where the spectacular buddleja trial has been such a treat. And in the same area, this year will be the last year for the trial of weigela with coloured or variegated foliage.

    In recent years there’s been quite a flurry of new introductions in this group, some with variegated foliage and some with purple foliage – and both, of course, also with spring flowers. Six entries to the trial have stood out so far.

    The old favourite known as Weigela 'Florida Variegata', with its creamy variegated leaves, has been popular for many decades and although it occasionally reverts, in general it’s very well behaved. Weigela florida 'Suzanne' is more vigorous, taller, and with a narrower variegation while ‘Sunny Princess’, also variegated, is relatively compact and its creamy edge is also relatively slender. The creamy variegated ‘Praecox Variegata’, with its honey scented flowers, also provoked admiration as did Monet (‘Verweig').

    Weigela Monet (‘Verweig'), dwarf, variegated, My Monet, Wisley, RHS, trial. Image: © Read More...

  • Autumn cabbage: awards and techniques

    Graham Rice on 13 Jan 2010 at 01:48 PM

    Autumn cabbage trial, RHS trials, Wisley, netting, pigeons. Image © Do not reproduce without permission.Autumn cabbage is a valuable crop at a time of year when the season of many summer vegetables is over. So almost fifty different cabbages intended to crop during September, October and November were trialled at Wisley last autumn. Both green and red cabbages were included. As is often the case with the Wisley trials, it wasn't just a matter of finding the best varieties but an interesting aspect of their cultivation was also revealed.

    Chickweed is a continuing problem on the trials field and this is especially important in relation to cabbages as it is thought to harbour cabbage white fly. So the young plants were planted in small holes in black landscape fabric which was laid across the planting area. The result was that cabbage white fly was not a problem. It also turned out to bring a double advantage as planting through the landscape fabric prevented cabbage root fly infestation and so the use of collars was not necessary.


  • Visitor voting: Amaranthus, Celosia and Dahlia

    Graham Rice on 06 Jan 2010 at 03:32 PM

    Amaranthus tricolor 'Early Splendor', RHS trials, Wisley, vote.A most valuable recent innovation at the Wisley trials has been the opportunity for visitors to vote for their favourites. I reported on the results of the buddleja voting back in December, now let's take a look at the voting for Amaranthus, Celosia and Dahlia.

    First off, I have to say that while placing the voting slips in the Pavilion at the bottom of the trials field (and not alongside the trials themselves) may have protected them from the weather, it noticeably reduced the number of votes cast. Nevertheless, the opinions of Wisley visitors are always valuable - and here they are.

    The visitors' favourite amongst the Amaranthus was not one of the familiar, cottage garden, Love-lies-bleeding types but A. tricolor ‘Early Splendor' (above). This variety sports dramatic cerise-scarlet foliage in the growing tips which darkens to bronze-purple later. "Vivid colour. Will stand out in a border" said one visitor, while another liked it because it was the "only one without alien Celosia 'Smart Look Red' - RHS trials, Wisley, vote. Image © Do not reproduce without permission.tentacles"!

    In Celosias, ‘Smart Look Red' (right) came out top. "Good bright colour. Many flower heads on compact plant. Good dark colour leaves" said one visitor who summed up its qualities well. I also liked the fact that it generated plenty of side shoots after the main dramatic flush and the combination of flower and foliage colour was certainly effective.

    In Dahlias, three shared first place. I discussed ‘Twyning's Revel' in my recent post on dark-leaved dahlias. ‘Will's Carousel' is a startling Collarette with petals Dahlia 'Pooh -  Swan Island', RHS trials, Wisley, vote. Image © Do not reproduce without purple, scarlet and white surrounding a ring of smaller white petals. ‘Pooh - Swan island' (left) also features an unusual colour combination and it's noticeable that none of these three remotely resemble traditional dahlias.

    Be sure to look out for more visitor voting opportunities in the coming season - and this year the voting slips will be placed alongside individual trials. I'll let you know which trials you can vote on when it‘s been decided.


  • Dark-leaved dahlias

    Graham Rice on 30 Dec 2009 at 03:04 PM

    Dahlia 'Twyning's Revel' - dark leaved dahlia. Image © Do not reproduce without permission.For so long it was the flamboyance of the flowers that was the attraction of dahlias and no one paid any attention to the leaves. These days we take it for granted that many of the best garden dahlias don't have boring green leaves - they have luscious bronze or purplish foliage which is a feature in itself.

    First ‘Bishop of Llandaff' caught gardeners' imagination and also ‘Yellowhammer' came along. Seed strains like ‘Redskin' appeared in catalogues, and the double orange  ‘David Howard' appeared at Great Dixter and other gardens.

    Now dark-leaved dahlias are taken for granted. Quite a number, large and small, have been seen in the Wisley trial in recent years and least two breeders, Aad Verwer in Holland and Keith Hammett in New Zealand, have devoted time to them.

    In this year's trial, as you'd expect - some did well, some not so well. None from the Dutch Happy Single (HS) series, raised by Aad Verwer in The Netherlands,  have yet been given an AGM but ‘Happy Single Kiss', salmon with a dark centre, ‘Happy Single Date', deep orange with a dark centre, and ‘Happy Single Wink', lilac with a purple centre, have come close.

    ‘Keith's Pet', from Keith Hammett, was given an AGM as a container plant but, though good, was less effective in the open ground. a star at Hampton Court in 2008 and another from Keith Hammett, with petals striped in lavender pink and white. These must be prime candidates for awards next year.

    Two others came close this year and will be examined again next year. ‘Twyning’s Revel’ (top) in soft coral red with a yellow centre and the gorgeous Dahlia 'Candy Eyes' - dark leaved dahlia. Image © Do not reproduce without permission.‘Candy Eyes (left)’, a star at Hampton Court in 2008 and another from Keith Hammett, with petals striped in lavender pink and white. These must be prime candidates for awards next year.

  • Award winning parsnips

    Graham Rice on 23 Dec 2009 at 12:02 PM

    Parsnip 'Albion' - Award of Garden Merit at the Wisley trialAs a staple of Christmas Dinner, this seemed a good moment to take a look at the awards that came out of  this year's parsnip trial at Wisley. Twenty one different varieties were grown, from old and familiar names like ‘Tender and True' to the very latest F1 hybrids. Ten were given Awards of Garden Merit (AGM).

    Seed was sown on 21 April at 2.5cm/1in intervals in rows 16in/40cm apart. And here's a crucial part of the growing regime: the whole crop was covered with Enviromesh as protection against root fly. It was briefly removed for thinning the seedlings to 3in/7.5cm in June, again once for weeding, and finally removed in September. The result: it proved very successful in keeping off the root fly.Enviromesh covering parsnips, protection against root fly. Image ©

    By the end of September the crop was ready to harvest although most gardeners will leave their parsnips in the ground and use them as needed. They will continue to bulk up in to the autumn.

    Almost half the entries were given AGMs, a testament to the progress in breeding parsnips in recent years. New award winners were: ‘Albion' (above): a uniform crop of unusually white, smooth-skinned roots; ‘Archer': good for the village Parsnip 'Lancer' - Award of Garden Merit at the Wisley trialshow as well as the table; ‘Lancer' (left): short, slender roots, ideal for baby-root crops; ‘Palace': good quality roots, with canker resistance; ‘Panache': very evenly tapered roots with smooth skins; ‘Picador': less tapered than many, so with more bulk per root.

    Four varieties which received the AGM in 1993 or 2001 were still considered good enough to retain their award. ‘Cobham Improved Marrow': elegant tapering roots and canker resistant; ‘Dagger': smooth roots with a shallow crown mean easy cleaning; ‘Gladiator'; the first F1 hybrid still has star quality; ‘Javelin'; another easy-to-wash variety with canker resistance.

    Finally, amongst those no longer considered of Award of Garden Merit standard was ‘Tender and True'. The expert panel of assessors considered that this was now outclassed, having been superseded by more modern varieties, but that it continued to sell well because of its appealing name.

    It's also worth noting that all the top varieties are F1 hybrids except ‘Cobham Improved Marrow' and ‘Lancer'. However, unlike many crops, the price difference between open-pollinated and F1 Hybrid varieties is relatively small so seed price need not be a serious factor in choosing varieties.

    Hoping you're enjoying home-grown Christmas parsnips. If not, you know which varieties to try for next year.


  • Superb spuria irises

    Graham Rice on 16 Dec 2009 at 02:24 PM

    Iris 'Hickory Leaves' - Award of Garden Merit. Image: ©RHSAmongst the many thousands of summer Iris cultivars, it's usually the flamboyant bearded irises that get most of the attention. But the recent trial of Spuria irises again proved what valuable perennials they are.

    Spuria irises are tall, up to around 1.5m/5ft, and while the flowers lack the rainbow colours and patterns of the Tall Bearded Irises their colours can be intensely penetrating in colour. They also have a more imposing habit than bearded irises, their slender deep green foliage setting off the flowers well


  • Buddleja – visitor voting and butterfly count

    Graham Rice on 10 Dec 2009 at 04:39 PM

    Buddleja 'Miss Ruby' - the most popular buddleia with visitors. Image: ©ProvenWinners.comThe figures have just become available for both the visitor voting and the butterfly count for the big buddleja trial at Wisley. Visitors were again asked to nominate their favourites and a count was also made of the number and type of butterflies visiting each variety.

    The visitor voting results were both very similar and very different to last year. In 2008 the top two varieties were ‘Miss Ruby', way out ahead, followed by Lo and Behold 'Blue Chip'. I wrote the results up on my Transatlantic Plantsman blog.

    This year top of the poll is again the vivid and prolific ‘Miss Ruby' but ‘Blue Chip' was way way down with less than 1% of the vote. ‘Blue Chip' was indeed good in its first year but in its second, when I saw it in mid July, it was very disappointing without a single flower open while many others looked spectacular.

    So ‘Miss Ruby' was again way out ahead with twice as many votes as the next placed ‘Raspberry Wine' and ‘Purple Prince' followed by ‘Burgundy' and ‘Santana'.

    Buddleja 'Orchid Beauty' - the most popular buddleia with butterflies. Image: © Read More...

  • The sweetest sweet corn

    Graham Rice on 02 Dec 2009 at 01:14 PM

    Sweet corn 'Seville' - one of the stars of the Wisley trial. Image: ©Victorian Garden NurseryAround the world sweet corn is such an important crop that plant breeders are constantly introducing new varieties. Many were on show in this summer's Wisley trial and an interesting feature was how existing AGM winners frtom previous trials have been outclassed by recent introductions.

    One of the stars of the trial was the supersweet variety ‘Seville' (left), described by the judging panel of vegetable experts as having "attractive, later maturing cobs with good shape and straight rows of small grains." Another independent assessment, from Stephen Shirley of Victorian Nursery Garden, confirms this view: "Seville is a fantastic variety of. Grows huge (as a plant), crops well with big cobs (3 per plant is about normal), has a good flavour and is hardy and easy to grow in cold years."

    Sweet corn 'Mirai White' - one of the sweetest in the Wisley sweet corn trial. Image: ©Thompson & MorganTrialled for the first time this year were four of a new type, the Mirai Series. These were all very early but also distinct in having very thin skins to the individual kernels. The panel noted that all four varieties were exceptionally sweet and tasty and that the eating experience was also enhanced by the thin skins. However, the thin skins also laid them open to disease infection and it was suggested that seed be sown in pots and young plants set out rather than sown direct into the soil.

    Only two of the Mirai Series are available at present. ‘Mirai Bicolour' was described by the judging panel as: "Very tender, with exceptional flavour.  Large, sweet, well-filled cobs." ‘Mirai White' (above) was described as having "Attractive white cobs... exceptionally tender and sweet... very good flavour."

    Others to perform especially well this year included ‘Conqueror',  ‘Lapwing', ‘Marshalls Honeydew' and ‘Sparrow' along with these varieties which already have an AGM following the last trial: ‘Earlibird', ‘Lark', ‘Northern Xtra Sweet', ‘Ovation', ‘Prelude' and ‘Swift'.

    And finally, those varieties which had previously been awarded an AGM - some as long ago as 1996, an eternity in sweet corn development - but which have now been superseded or which are not now available having been outclassed: ‘Dickson', ‘Dynasty', ‘Gilden Giant', ‘Golden Sweet', ‘Gourmet', ‘Mainstay' and  ‘Start Up'.

    Look out for these top performing varieties when ordering seed for next year. I'll let you know when the ratified AGM awards become available.


  • First season stars in the Wisley clematis trial

    Graham Rice on 25 Nov 2009 at 02:52 PM

    Clematis 'Jorma' - star of the Wisley clematis trial. Image: ©GardenPhotos.comNow that the assessment panel - which includes some of the country's leading experts in shrubs and climbers - has finished this year's sessions on the trial of Clematis viticella varieties, it's a good time to pick out those which they think have done best this year. I gave an early personal assessment, but the team has been checking the trial all summer right into the autumn.

    The star of the show so far has been ‘Jorma' (left, click to enlarge).  Its beautiful bluish-violet flowers were especially impressive and very uniform in colour with attactive stamens. However, the view was that this is not really a Viticella clematis but a Jackmanii type.

    Two old also favourites did well. ‘Alba Luxurians', white with green marks, was at its peak in mid August and still impressive a month later while the wine-red ‘Kermesina' also proved long flowering - its long season perhaps distinguishing it from the otherwise similar ‘Rubra'.

    Clematis 'Romantika' - a highlight of the Wisley clematis trial. Image: ©GardenPhotos.comSimilar to ‘Alba Luxurians' was ‘Luxuriant Blue' (entered as ‘Caerulea Luxurians') but with a blue tint to the white and green flowers indeed ‘Alba Luxurians' is one of its prents (the other is the rarely seen ‘Neodynamia').

    The deep purple blue ‘Blue Belle' proved better than the rather similar ‘Kiev' but became rather lanky later in the season while ‘Elvan', with pretty purple flowers striped in white, has nodding flowers so is best viewed from below. It was another with a very long season.

    ‘Hagelby Pink' was the best pink this year, and still had plenty of buds coming in mid September. It also flowererd all the way up the plant, a valuable feature. The panel agreed that it would look growing with the dark purple ‘Romantika' (above, click to enlarge), another Jackmanii type, which also stood out this year.

    In general the assessors noted that watering was a big help in extending the flowering period of these plants; on the trial this was provided soil level irrigation. But they decided that now that the plants are well established, next year they would not be watered unless absolutely necessary. This would provide a more realistic test.

    The plants will all be cut back to 15cm/6in in the spring - just as they would be in the garden. Next year's display promises to be even more colourful.


  • Last days of the pampas grass trial

    Graham Rice on 18 Nov 2009 at 02:34 PM

    Cortaderia selloana 'Evita' - the star of the Wisley pampas grass trial. Image: ©GardenPhotos.comThe trial of Cortaderia, pampas grass, has been both dramatic and intriguing. As it comes to a close, with some entries still looking good very late in the year, there was one that stood out above all the others - ‘Evita' (click the picture to enlarge). Except part of the point is that it didn't "stand out" at all - some varieties are huge, 3m/10ft tall, but ‘Evita' is altogether more manageable.

    Reaching just 4-5ft/1.2-1.5m high, it combines vigour, dwarf habit, prolific flowering with plumes of good substance and also flowers as a young plant - a very valuable feature. Another notable feature is that ‘Evita' plants are female, but are not known to produce seed. I'm certain this will get an Award of Garden Merit.

    One of the interesting things about cortaderias is that plants are either male or female so any seedlings produced will be hybrids. So when nurseries raise named varieties from seed the resulting plants will not come true - and there was some dramatic evidence of this in the trial; no awards for those entries.

    But others that looked especially good included. ‘Highfield Pink' which was seen as the best pink-flowered form - and one assessor said it had an "Afghan Hound quality"! The variegated ‘Pink Phantom' also impressed.

    Cortaderia selloana Silver Feather 'Notcort' - the best for foliage in the Wisley pampas grass trial. Image: ©GardenPhotos.comThose with variegated foliage must obviously be propagated by division and two of these stood out. Silver Feather (‘Notcort') is a white variegated form of C. pumila and the overall impression of the rather discreetly marked leaves was of grey foliage. It flowered well, did not grow too high (in fact it was one of the smallest) and its foliage was excellent.

    The other good variegated plant was ‘Gold Band'. More vigorous than other variegated types, the overall effect was a wonderful golden colouring and the flowers were excellent too.

    These were the stars of the trial and as well as identifying some excellent plants small enough for most gardens and which will give colour from both flowers and foliage, it really highlighted the necessity for nurseries to propagate by division and not seed.

    I'll bring you news of the final awards once they're confirmed. In the meantime, take a look at the full list of plants in the Cortaderia trial.


  • Two fine late flowering kniphofias

    Graham Rice on 11 Nov 2009 at 12:31 PM

    Kniphofia rooperi - a fine very late flowering poker. Image: ©GardenPhotos.comA week or two back I wrote about delphiniums which came back for a second burst of flowers long after their main flush in June. The last couple of times I was taking a look at the Wisley flower trials I also noticed some other perennials looking good late in the season.

    The Kniphofia trial has been a difficult one to assess because these pokers flower over such a very long season - some are at their peak in late spring, some in mid autumn.

    In September and October Kniphofia rooperi (above, click to enlarge) has been spectacular. You can see from the picture how vivid it is and how few other kniphofias there are flowering in the background.  This is a splendid plant for autumn colour and because this form in the trials, sent to the trial by the Hampshire nursery MacGregor's Plants for Shade, was so good it was decided that it needed its own cultivar name. As yet, we don't know what that will be. But this plant was certainly better than the variety ‘Torchlight' growing alongside.

    Kniphofia caulescens (from John May) - good foliage and good flowers. Image: ©GardenPhotos.comThe other poker at its peak late in the season was K. caulescens, and in particular the form loosely known as "from John May". This is very different from many pokers in that not only are its spikes at their best in the autumn, but its impressive foliage is a valuable feature for many months.

    Its leaves are relatively broad and noticeably greyish in colour, sometimes they look rather like the leaves of leeks, and can be very dramatic. You can see them in the background in the picture. And it turns out that his plant is unusual in another way: in South Africa, where it grows wild, it's seen in large colonies in bogs - far wetter conditions than we normally associate with kniphofias.

    Both these late flowering pokers look to be well on their way to gaining the Award of Garden Merit and will bring a little fiery style late in the season.


  • Awards for irises

    Graham Rice on 06 Nov 2009 at 12:09 PM

    Iris 'Helen Dawn' - Award of Garden Merit winner 2009. Image: ©RHSTall Bearded Irises are amongst the most dramatic and colourful of perennials so the very best of them must be really impressive. And they are.

    The RHS Iris Sub Committee - yes, there's a sub committee just for irises - has recently had its latest awards ratified and three Tall Bearded Irises performed so well in the trial at Wisley that they've been given the Award of Garden Merit.

    They were planted in 2007 on the Portsmouth Field, usually known just as the trials field, and were assessed regularly during the flowering season. Using a points system, four specific qualities assessed: the overall quality of the plant, stem quality (robustness and branching), flower quality and the presentation of the flowers.

    And out of 110 entries into the trial three gained an AGM, while one other had its AGM withheld until it becomes available to buy.

    The lovely ‘Helen Dawn' (above, click to enlarge) is almost pure white. Reaching about 90cm/3ft, with six to eight buds on each stem, the standards (the three upper petals) are almost pure white while the falls (the three lower petals) are slightly creamier with an attractive network of pale veins. The white beard is yellow at the tip, deepening almost to orange in the throat, and the flowers have what iris-expert Claire Austin calls a "heavy sharp scent".

    ‘Helen Dawn' was raised by Australian breeder Graeme Grosvenor and registered back in 1998. It's a cross between ‘Skating Party' and ‘Scandia Delight'.

    Iris 'Diabolique' - Award of Garden Merit winner 2009. Image: ©RHS‘Diabolique' is almost the opposite in colour. The nearly-black buds open to heavily ruffled deep wine purple flowers, the falls slightly richer and more vinous than the standards. The blooms have good substance so are unusually weather resistant while the deep blue beard is short, but its colour stands out well. Reaching about 38in/97cm and with up to nine flowers on each stem, ‘Diabolique' makes quite an impact.

    Raised by the prolific Schreiner's Gardens in Oregon, ‘Diabolique' has ‘Amethyst Flame' and ‘Melodrama', amongst others, in its background.

    Also from Oregon is the last of the three Tall Bearded Irises to be given an AGM for 2009, ‘Paul Black'. This is taller, at 4ft/1.2m, with up to six buds per stem and is basically dark purple-blue with a fiery orange beard - like a flame in the night. Both the standards and the falls have a slightly inky look but fade to white in the throat. ‘Paul Black' was raised by Thomas Johnson and named for his partner at their iris nursery Mid-America Garden in Oregon


  • Dahlias in containers

    Graham Rice on 28 Oct 2009 at 11:29 AM

    Dahlia 'Spanish Conquest' in the Wisley trial of dahlias in containers. Image: ©GardenPhotos.comThis year's dahlia trial at Wisley has been unusually fascinating and I'll be reporting on a number of its features over the next few weeks. Picking up on recent trends, this year twenty one of the entries were grown as individual plants in pots to assess their value as container plants.

    Immediately one thing is obvious. These plants, of course, are smaller than most dahlias - if they were 4ft/1.2m tall, as are many varieties, they'd be far too large for most containers. So we tend to look down on the flowers from above. But many varieties hold their flowers so they face sideways - ideal on a tall plant which is viewed from the side but the impact is much reduced when you look down at the flowers on a short plant from above.

    ‘Spanish Conquest' (above, click to enarge) was one whose flowers are more upward facing and which made a real impact. The colour is wonderful too, with red buds opening to old gold flowers with burnt orange centres. The plants were prolific and seemed to cope with dry conditions better than many. I thought it the best of all those grown in containers this year.

    Dahlia 'Keith's Pet' in the Wisley trial of dahlias in containers. Image: ©GardenPhotos.comOn the other hand there was ‘Keith's Pet'. This is a lovely dainty little dahlia with neat dark purplish foliage and bright white flowers with just a hint of pink showing through from the backs of the petals. But the flowers face sideways and unless you get down on your hands and knees - as I did to take the photograph - you never get the full impact of the flurry of flowers.

    Other outstanding varieties in containers were ‘Exotic Dwarf', a single yellow with upward facing flowers, ‘My-nute Blend', a very prolific red and yellow double, and also ‘Gallery La Tour', with upward facing pink and white double flowers over dark leaves.

    There were a couple of other points that came out of this trial of container grown dahlias. There was no watering system set up, no drip nozzles so that the pots could be easily watered at the turn of a tap. The result, I'm afraid, was that with pressure of work meant that the watering can just didn't come out often enough and many varieties would have been a great deal more impressive if properly watered.

    And as we assessed them we also noticed the compost in the pots. It had shrunk so much that there was a large space between the tops of the pots and the compost. We concluded that the peat-free compost had already started to decompose and so had shrunk - not good for the plants. The begonias hated the peat-free compost this year as well. Sometimes, nothing but peat, or at least a good proportion of peat, will do.

    Of course the varieties that could cope with these problems really were impressive.


  • Double display from delphiniums

    Graham Rice on 21 Oct 2009 at 01:57 PM

    One of the glories of the Wisley trials field in early summer are the delphiniums. Tall and magnificent - taller than they ever get in most people's gardens, I have to say, what with all that manure - they're a real spectacle. But then after a few weeks of glory, they're gone. Or are they?

    Delphinium 'Amadeus' flowering in September in the Wisley trials. Image: ©GardenPhotos.comI went back to take a look at the delphinium  trial in mid September, and then finally at the very end of the month, and found some varieties again looking very impressive. OK, the quality of the individual spikes was not up to the standard of the main display but they nevertheless made a real impact.

    On my first September visit ‘Ann Woodfield', blushed white, and ‘Kestrel', electric blue with a dark eye, stood out while at the end of the month ‘Jenny Agutter' (right), in rich pink, and ‘Amadeus' (above), in deep purple blue, were the stars. Delphinium 'Jenny Agutter' flowering in September in the Wisley trials. Image: ©

    So what can we do to help ensure we get a double display from our delphiniums? First, cut off the main spike as it fades and then when the shorter, slimmer secondary spikes that follow also fade away - cut the whole plant back down to ground level.

    This may seem an odd thing to do in mid summer but if the plants are kept watered, and fed with a high nitrogen fertiliser if the soil is not as rich as that at Wisley, they will soon sprout fresh new leaves. These are valuable in themselves and then followed by more flowering spikes later. Be sure to look out for mildew in hot dry spells and also for caterpillar damage. Then you've every chance of getting a double delphinium display from your plants.


  • New (free!) dahlia bulletin

    Graham Rice on 12 Oct 2009 at 04:52 PM

    Open-Centred Dahlias - new Plant Bulletin from the RHS. Image: ©RHSDahlias are becoming increasingly fashionable. In particular, single-flowered and collarette dahlias are catching everyone's eye so after trialling many of them in recent years the RHS has produced a twelve page full colour bulletin entitled Open-centred Dahlias.

    Written by Wisley's Sue Drew, from RHS Trials Office, who has special responsibility for the dahlia trials, the bulletin covers both single-flowered types and collarette dahlias (collarettes are those with additional shorter petals around the eye).

    This excellent guide starts with a short history of the dahlia and then illustrates all the thirteen different flower forms, to show the amazing range available. A wide range of the best singles and collarettes is illustrated and each is briefly described, all those chosen have either already been honoured with an Award of Garden Merit or look well set to gain the award soon. Suppliers are noted for each variety - very useful. There's also a very good guide to growing dahlias, a discussion on breeding new dahlias and some thoughts on planting partners for single dahlias.

    The whole bulletin provides a valuable introduction to these long flowering and prolific plants, all written in an easy to follow style and with plenty of excellent pictures.

    What's more, you can download this new Dahlia bulletin FREE from the RHS website. Or check out the RHS Plant Bulletins page for a list of all the free Plant Trials Bulletins on offer.

    Yet another excellent RHS Plant Bulletin based on the society's trials.



  • Intriguing ipomoeas

    Graham Rice on 07 Oct 2009 at 03:54 PM

    The trial of annual climbers at Wisley has thrown up some stars and some disappointments. Both extremes are to be found amongst the ipomoeas.

    Mina lobata in the Annual Climbers trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comIn recent years botanists have decided that, although superficially it looks very different, Mina lobata is so closely related to Ipomoea that it should be moved into the genus Ipomoea as Ipomoea lobata (left, click to enlarge). It's been a real star, with spikes of flowers featuring bright red buds opening to cream. Three very similar entries were included in the trial and in recent weeks all three have been stunning and all three look to be on track for an Award of Garden Merit. And all three looked impressive all day.

    Also pretty impressive was Ipomoea ‘Ismay Soft Blue' (below, click to enlarge), with its white flowers neatly barred in blue and late in the season it seemed to have the most flowers on show of any ipomoea. Ipomoea 'Ismay Soft Blue' in the Annual Climbers trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comThe deep purple ‘Kniola's Black Night', with its white throat, set against small, dark foliage was also good. This and the other familiar trumpet-flowered ipomoeas all open very early in the day and on hot sunny days have crumpled by lunch time although on cool days ‘Ismay Soft Blue', in particular, lasted till the end of the day.

    However our old favourite ‘Heavenly Blue' - such a stunning colour - and many of the other ipomoeas proved too leafy on the rich Wisley trials field soil and, as happens with nasturtiums, the leaf stalks stretch and so the leaves tend to hide the flowers. The same thing happened with the thunbergias. The ipomoea leaves themselves also grew larger than normal and there seemed to be far more of them. The result of all this extended leafy growth was that the flowers were often hidden. Some were also rather variable in their flower colour or patterning and these included ‘Flying Saucers' and ‘Azzurro di Venezia'.

    Those Ipomoea lobata may have started later than most of the annual climbers but the autumn display is amazing.


  • Amaranthus - bold and beautiful

    Graham Rice on 30 Sep 2009 at 10:34 AM

    Amaranthus 'Golden Giant' in the trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comWe all know the old cottage garden annual Love Lies Bleeding, Amaranthus caudatus. But down on the Wisley trials field right now is a trial of these impressive and easy-to-grow annuals - with almost thirty other entries alongside that familiar favourite.

    They come in an amazing variety. As well as the long deep red tassels of Amaranthus caudatus there's a pale green form and a spectacular range of type with upright plumes in crimson, green, and biscuit brown plus some with tight, upright rather nobly flowers heads. There's also a range of varieties with coloured foliage.

    One striking thing about the trial is that the mixtures are all noticeably poor compared with the single colours. They vary so much in height and style of flowering that in a group they just look terrible. So forget about ‘Mixed', ‘Ribbons and Beads' and ‘Pony Tails'.

    Amaranthus 'Oeschberg' in the trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comAmongst the those with biscuit brown plumes ‘Golden Giant' (above) was definitely the pick. ‘Marvel Bronze' features tall deep red plumes and bronze-red foliage which makes a great combination as does the rather similar ‘Oeschberg' (left).

    A few varieties of the less robust Amaranthus tricolor were also included, these are the ones with multicoloured foliage but insignificant flowers. ‘Early Splendour' was probably the pick but they all develop a rather ungainly habit and none had the impact of the flowering types.

    One thing to keep in mid is that most of these make big plants - 90cm-1.2m/3-4ft is common so they need space. But in a large container, slipped into spaces in mixed borders or as part of a tropical style summer border these are very effective.

    You'll enjoy seeing these impressive annuals, take a stroll down to the trials while they're still looking good. And there are voting forms at the back of the Trials Pavilion so you can tell us which is your favourite.


  • Late flowering pinks

    Graham Rice on 23 Sep 2009 at 08:39 AM

    Dianthus 'Gran's Favourite' - still flowering in mid September. Image: ©Whetman PinksOne of the benefits of looking over the trials regularly through the season is that it's possible to pick up points that would be missed by simply checking the trials while they're at their most colourful. So the other day I cast my eye over the trials of pinks, three months after their peak flowering period, to see which varieties were still performing well.

    In general it was very obvious that the dwarf pinks, most of which are relatively new varieties, had far fewer flowers than the garden pinks - most of which have been around for a few years.

    So the two with the most impact at this late point in the pinks season were ‘Gran's Favourite' (above) and ‘Houndspool Ruby' (below left), both well known varieties and both already holding the Award of Garden Merit.

    Dianthus 'Houndspool Ruby' - still flowering in mid September. Image: ©Whetman PinksOthers that stood out were ‘Doris', ‘Moulin Rouge' and ‘Valda Wyatt' - again all three already hold the Award of Garden Merit and I expect that these long flowering qualities have already been noticed by the experts who've been assessing this trial over the years.

    As I say, the more modern dwarf pinks were less impressive this month compared with June and July but the three that featured the most flowers were ‘Red Star', ‘Passion' and ‘Starburst'

    But the lesson seems clear. If you'd like to have pinks which are not only covered with flower in their peak period in early summer but which carry on their display into the autumn, choose AGM winning garden pinks like ‘Gran's Favourite' and ‘Houndspool Ruby'. But remember too: all pinks will flower more prolifically if regularly dead-headed



  • Dazzling celosias

    Graham Rice on 16 Sep 2009 at 10:48 AM

    Celosia trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comCelosias used to thought of mainly as pot plants, and they were also favourites for decorating events at town halls and other municipal venues.

    But I grew celosias as summer annuals in mixed borders a few years ago and they were superb. As the summer climate improves and as more adaptable varieties are introduced, growing a trial out in the open on the trials field has provided one of the most colourful of the summer's trials. They come in two types, the feathery plumes of the Prince of Wales Feather type, and the Cockscomb type with congested flower spikes that, some people say, look like the inside of your brain!

    Forty eight entries were grown, all started from seed in March and treated as half-hardy annuals. Most were of the feathery type and come in vibrant red, orange, gold and yellow shades and their dazzling colours catch the eye as soon as the trials come into view. There are a few softer colours, though these seem less effective, and one lovely tall pink and white form.

    Looking them over yesterday, we had an eye for both flower and foliage colour, long flowering season and an effective display of plumes. Uniformity is also important, in two ways: there should not be too much variation in colour of the single colour types and if the flowers were supposed to be feathery plumes there should be no cockscomb types creeping in to spoil the impact.Celosia 'Flamingo Feather' in the Celosia trial at the RHS Garden at Wisley. Image: ©

    There were five which especially caught the eye of the assessment panel. ‘Smart Look Red' featured long lasting bright red flowers set against rich burgundy foliage to create an unforgettable combination. The vivid slightly pinkish red spikes of ‘Glow Red' were much admired while ‘Century Red' was neat enough for small containers or small sunny beds around the patio with bronze foliage setting off the bright red flowers. The vivid marmalade coloured plumes of ‘Fresh Look Orange' were very striking set against fresh green leaves.

    ‘Flamingo Feather' (above, click to enlarge) was rather different, taller than most of the others and with masses of slender spikes, the carmine buds open to pink flowers fading to white. Good for cutting, it also integrates especially well with perennials in mixed borders.

    The assessors rated those five especially highly, but you can vote for your own favourites. Pick up a voting form in the new logia at the bottom of the trials field, make your choice, add your comments and leave it in the box alongside the celosia trial itself.



  • Kniphofia (red hot poker) Open Days

    Graham Rice on 07 Sep 2009 at 10:39 PM

    Alongside a new look Wisley Flower Show, starting this coming Friday morning and closing on Sunday afternoon, the RHS Herbaceous Plant Committee is running a series of three Kniphofia Open Days. Kniphofias are dramatic, colourful, sometimes statuesque perennials which are currently enjoying a revival so this is an ideal time to combine a visit to the Wisley Flower Show with finding out more about these essential autumn perennials. There are two parts to the event.

    Kniphofia 'Bees' Sunset' in the Kniphofia trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comIn the loggia at the end of the Wisley Canal, just a short walk from the main entrance to the Wisley Garden, there'll be a series of illustrated display boards giving a thorough and easy-to-follow introduction to kniphofias. Members of the RHS Herbaceous Plant Committee will be on hand each day to provide expert advice so, to mention just three, you'll get the chance to pick the brains of Sarah Cook, former Head Gardener at Sissinghurst, Ivan Dickings former Chief Propagator at Notcutts Nurseries and plant breeder Simon Crawford.

    They'll be able to tell you about where kniphofias grow in the wild, how best to grow them in gardens, which varieties did well in the trial and answer your questions about kniphofias, how to grown them and the plants that look good with them.

    Also, at 11am and 2pm each day, meet at the loggia for a Guided Walk through the Kniphofia trial where you'll be able to see every one of the one hundred and twenty seven (yes, really - I know, you had no idea there were so many!) entries in the trial and get an insight into why some got high marks in the trial and some did not. There'll be some stupendous varieties at their peak.

    So that's Friday 11th, Saturday 12th and Sunday 13th of September - start at the loggia at the end of the Wisley canal: enter the gardens, turn right along the back of the main building and look to your left towards the end of the canal.



  • Annual climbers

    Graham Rice on 02 Sep 2009 at 12:40 PM

    Rhodochiton atrosanguineum - in the Wisley Annual Climbers trial. Image: ©GardenPhotos.comMost trials concentrate on a particular type of plant - usually one genus like Dahlia or Dianthus. But occasionally a whole group of similar plants from a wide variety of genera is trialled together because they have useful similarity - and this year it's the annual climbers.

    These are invaluable  in creating a quick feature in a new border, rapidly clothing a fence or wall, or for adding a secondary colour to a mature shrub or climbing rose.

    There are one hundred and fifteen different entries covering about twenty different genera grown on wire towers and they've been fascinating. The site is perhaps a little too exposed for some of them, but many are thriving - indeed the Eccremocarpus are thriving a little too enthusiastically, they're very vigorous and the rich soil is helping create large plants.

    Not many years ago Rhodochiton astrosanguineus (above) was mainly grown in pots in the cold greenhouse as it was considered impractical to grow it outside - on the trial, it thrives. In recent years more robust forms have been selected.

    Ipomoea 'Heavenly Blue' - in the Wisley Annual Climbers trial. Image: ©GardenPhotos.comOf the forty Ipomoea entries, ‘Bohemian Shades', ‘Grandpa Otts' and I. lobata stand out with many of the others also impressing. ‘Heavenly Blue', however, is not showing itself off as well as we know it can and the judges described ‘Split Personality'  as "ugly"!


  • Vote for your favourite

    Graham Rice on 28 Aug 2009 at 04:52 PM

    Buddleja trial at the RHS Garden, Wisley. Image: ©GardenPhotos.comOne of the most exciting developments on the Wisley trials in recent years has been the new opportunity for visitors to vote on their favourite plants.

    For a number of selected trials, voting papers and a voting box are set up alongside the trial. Just tell us your favourite, add a quick comments to tell us why you like it - and all the votes will be tallied and published, along with the comments, at the end of the season.

    Voting on the Buddleja trial is going on now. It'll be interesting to see how this year's vote compares with last year's voting. The Buddleja trial is not on the trials field with the perennials, annuals and veg. It's at the opposite end of the garden, past the restaurant and through the Pinetum. You'll also find the trial of Weigela down there - this trial focuses on the coloured-leaved forms (purple, variegated etc) which have become so popular recently - along with the trial of Indigofera, much under rated shrubs in the pea family, which is looking good now.

    Amaranthus with colourful foliage and flowers. Image: ©GardenPhotos.comOn the main trials field, you can vote for Amaranthus and Celosia. The Celosia trial is especially interesting as this is a plant  which is much underused in summer borders - the trial show how good some of them are. And with both flower and foliage appeal, the Amaranthus are also in need of your vote.

    Voting on the Dahlia trial is about to start and in October voting will begin on the Cortaderia (pampas grasses).

    This is a great opportunity to make your views known, please cast your vote and tell us what you think.

  • Online pea trial

    Graham Rice on 20 Aug 2009 at 07:21 PM

    Pea 'Sugar Ann'. Image: ©RHS TrialsEvery year the RHS tries to accompany its huge trials programme with ventures at its regional gardens and also at East Ruston. And every year we also try to involve RHS members in a trial, to give gardeners and schools around the country the chance to compare varieties, report back and have their results included as part of the assessment of varieties for the Award of Garden Merit.

    This year it was snap peas and sugar peas and 200 members along with schools around the country grew two varieties and kept records of how well (or how badly) they did. The varieties grown were ‘Sugar Ann' (above) and ‘Oregon Sugar Pod', both widely listed in catalogues.

    Pea 'Oregon Sugar Pod'. Image: ©RHS TrialsWell, reports are starting to come in. And, without giving the game away before all the results are received and collated, the comments so far have been very interesting. Some people found that just as the seedlings were emerging they disappeared: sounds like slugs or mice or pigeons to me. Some growers re-sowed.

    Both were rated "sweet" in reports and also as and "stringy" (!) and interesting details were revealed: one grower reported that ‘Sugar Ann' could be eaten very early or allowed to mature and it seemed that ‘Sugar Ann' was also a favourite with pigeons and slugs. Another reported plants of  ‘Oregon Sugar Pod' with pink flowers instead of the usual white - a sign that this variety is deteriorating.

    But there are still reports to come - so if you participated in this trial please get your reports in as soon as possible. The hard-working team in the Trials Office (not to mention Thompson & Morgan who generously donated the seeds) have put a lot into this - and you've put a lot into growing and assessing the crop. So please don't fall at the last hurdle, get those reports sent in. the more reports we have, the better picture we can create of how these two varieties performed across the country.


  • Early favourites in the veg trials

    Graham Rice on 14 Aug 2009 at 03:03 PM

    Lots going on amongst the vegetable trials at the moment.

    Cucumber 'Cucino' - looking good in the Wisley trial. Image: ©Thompson & Morgan.The all-female cucumber trial is being grown in a polythene tunnel in the way that most keen home veg gardeners will grow them. This is not a sophisticated commercial poly tunnel with heat for chilly early summer night, and fans to keep the air moving and sides which roll up for ventilation. If you need some air, open the doors! So this is a good test of which varieties will suit home gardeners and there are some early leaders.

    For flavour, ‘Byblos' (below), ‘Carmen', ‘Emilie', ‘Mini Munch', ‘Naomi', ‘Socrates' and ‘Tyria' stood out. For productivity ‘Cucino' (above) and ‘Mini Munch' got special mention from the assessors, while ‘Tiffany' was appreciated for its even shape. All these were thought to be a cut above the others amongst the twenty two varieties in the trial


  • Trials at East Ruston in Norfolk

    Graham Rice on 06 Aug 2009 at 03:45 PM

    Pinks in the RHS trial at East Ruston in Norfolk. Image: ©RHS TrialsThe trials at the RHS garden at Wisley in Surrey, just off the M25, are the most impressive trials of garden plants in the country, probably in the world. But the RHS also has a secondary trials site in Norfolk at the gardens at The Old Vicarage at East Ruston.

    Thanks to the continuing generosity of  owners Alan Gray and Graham Robeson, a range of trials is again planted at the garden for visitors to enjoy.

    The trial of garden pinks is still in bloom and, in fact, the extent to which these plants are still blooming a couple of months after their June peak will play a significant part in which are awarded AGMs and which are not. Varieties with a long flowering season have quite an advantage.

    Ipomoea 'Star of Yelta'. Image: ©GardenPhotos.comThe trial of annual climbers, which is such a fascinating feature at Wisley, is replicated at East Ruston and the ipomoeas - look out for the sumptuous colouring of ‘Star of Yelta' (left) - should be at their peak through this month along with Eccremocarpus and many others.

    It's only the first summer of the perennial Phlox trial and, as at Wisley, their peak will be next year and the year after but it will be interesting to see if the kniphofias raised from seed - about which I was so rude here recently - are just as bad at East Ruston as they are at Wisley!

    Amongst vegetables, there are two intriguing trials at East Ruston which will be worth seeing this month. The melons and watermelons will be at their peak, and this trial is restricted to the small-fruited, one-person varieties which have such wide appeal.

    There's also a trial of sweet corn which will be well worth a look, it focuses in particular on the super sweet types which really do have the best flavour.

    Next month check which pinks are still going, many annual climbers will still show plenty of colour, the trial of June-sown calabrese will be at its peak as will the trial of cabbage, including red cabbage, for autumn cropping.

    The garden at East Ruston is always worth a visit and the chance to check out some of the RHS trials - without negotiating the M25 - makes a visit all the more worthwhile.


  • Trials reveal plants to avoid (as well as AGM winners)

    Graham Rice on 31 Jul 2009 at 12:11 PM

    Kniphofia 'Flamenco' - as it was when first introduced. Image: ©Benary Samenzucht GmbHOne of the interesting things about the Wisley trials is that not only do they highlight plants which are deserving of an Award of Garden Merit (AGM) but they also highlight plants which are unusually poor  and so serve as a warning to gardeners not to grow them. The Kniphofia trial, one of the season's most colourful and interesting trials, is a case in point.

    Most kniphofias are intended to be propagated by division so that the plants are guaranteed all to be the same. But the trial also includes four entries of kniphofias raised from seed - and these are just not worth growing. The varieties are ‘Border Ballet', ‘Flamenco', ‘New Hybrids' and ‘Royal Castle Hybrids'. ‘Border Ballet', raised by one of the great British plant breeders, the late Ralph Hurst, and ‘Flamenco', which received an award from the European flower trialling organisation Fleuroselect, used to be excellent - but not any more.

    The trouble is that over the years the quality of the stock has deteriorated so much, now the heights and colours and the flower power of the individual plants are far too unpredictable. There are twelve plants of each variety in the trial and last time I checked many weren't flowering at all. ‘Flamenco' was just one that disappointed - the picture (above, from its raiser) shows how good it once was.

    The lesson: grow named kniphofias propagated by division. This is the last year of the trial so there'll be some award winners to tell you about in the autumn.

    Begonia 'Sensation Red' - withdrawn from the trial with mildew. Image: ©RHS TrialsAnother trial which revealed some plants to steer well clear of was the trial of begonias for pots and baskets - which I have to say is absolutely spectacular and well worth a visit. It's been sprayed against mildew but in spite of that precaution two varieties have already been removed owing to severe mildew infection. So if you're thinking of growing the new ‘Martha White' ("bad mildew, plants looking v poor" say the judges' notes) or the popular ‘Sensation Red' ("very bad mildew ") - beware: last week they were taken away and disposed of.

    With this in mind, the judges decided to cease spraying the begonias and so make it easier to assess which really are susceptible to mildew and which are not. And growing almost a hundred varieties together is a severe test. We'll see how it goes...


  • Clematis trial is impressive

    Graham Rice on 27 Jul 2009 at 03:35 PM

    Clematis trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comGrowing a trial of climbers can be difficult, especially if there are a lot to include, but the staff looking after the trial have come up with good solution for the more than sixty varieties of Clematis viticella and its hybrids.

    Each variety is grown on a tall narrow wire mesh column, guided up to the top about 2m/7ft from the ground, then as the shoots stretch up and beyond they're guided back down again. The result is that the flowers stand out from the supports, from the foliage and the stems making them easy to examine and it's also easy to quickly assess just how much bloom each variety is producing. I have to say that I was sceptical when I first saw it all in place, but it really seems to work.

    The one that stood out for me when I looked was Jenny (‘Cedergren'), for although it was less prolific than some the blue flowers, each with an almost white stripe down the centre of each petal, were lovely.

    So far, and we're only half way through the first year of assessment, the panel of expert assessors has been especially impressed by mix of the familiar and the less widely grown.

    Clematis 'Purpurea Plena Elegans' in the trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comSome old favourites, and existing AGM winners, like ‘Madame Julia Correvon' (wine red) and ‘Purpurea Plena Elegans' (double purple, left) have been well received. The more recent favourite ‘Polish Spirit (purple-blue), another existing AGM winner, was noted as flowering all the way down the plant. Less widely grown varieties that were much admired were ‘Viola' (violet blue), the dainty ‘Odoriba' (white with a pink rim) and ‘Walenburg' (cream, edged magenta-purple) as well as ‘Poldice' (white with a purple rim) which I'd never seen before.

    This is a group of clematis that's ideal for growing through other plants like a climbing rose or shrub rose. They're easily managed, you simply cut them back hard every winter or early spring and pull out all the old growth. Seeing them all growing side-by-side in this trial allows you to choose exactly the variety that's ideal in your own garden.


  • Buddlejas in bloom

    Graham Rice on 20 Jul 2009 at 01:19 PM

    Buddleia trial at the RHS Garden at Wisley. Image: ©GardenPhotos.comThe trial of buddlejas at Wisley is located about as far from most of the other trials as it's possible to be. While almost all the other trials are on the trials field, beyond the double herbaceous border and Battleston Hill, the buddlejas and some other shrubs are through the Pinetum at the opposite end of the garden. But it's well worth the walk.

    I took a look just a few days ago and the colour and the scent and the bee buzzing were overpowering. Some varieties were in full flower, some were just getting going while only a few were still to open their first buds.

    There are over one hundred and twenty buddlejas in the trial and the ones that struck me as especially impressive were: ‘Blue Horizon' and ‘Darenth Valley' (white), both with a very upright habit so neighbouring plants are not smothered; ‘Dart's Papillon Blue' in a lovely cool blue shade; and the vivid hybrid ‘Miss Ruby'.

    It was especially interesting to see the very short varieties. The grey-leaved ‘White Ball' was just knee high and covered with white flowers while Peacock (‘Peakeep') with its large cones of vivid purple flowers was the same height.

    Buddleia Peacock ('Peakeep') and 'Pink Delight' at the RHS Garden at Wisley. Image: ©GardenPhotos.comPeacock (‘Peakeep') is one of the British-bred English Butterfly Series, from East Malling in Kent. These are supposed to be noticeably shorter than other buddlejas but while Peacock (‘Peakeep') was about 60cm/2ft high and one of the best on show, Marbled White (‘Markeep'), friom the same series, was more than twice the height and reached 1.68m/56in.

    The other significant dwarf entry in the trial is Lo and BeholdTM 'Blue Chip', a new multi-species hybrid from the USA, which came second in the visitors' favourites vote last year. The odd thing was that while so many other entries were looking spectacular and most of the rest showing plenty of colour - on Lo and BeholdTM 'Blue Chip' there was not a single flower open and only the very first signs of buds.

    Unfortunately, the two new dwarf buddlejas from Thompson & Morgan are too new to be included in the trial and with this being the trial's last season there's no chance for them to be added.

    But right through the summer this trial will be worth a look. And with coloured foliage weigelas growing alongside, and some lovely specimen trees and summer heathers to appreciate on the way, be sure to take a right turn out of the restaurant and enjoy the stroll.


  • Brilliant begonia

    Graham Rice on 07 Jul 2009 at 11:10 PM

    Been a busy week... I've been covering all the new plants on show at the Hampton Court Palace Flower Show over on my RHS New Plants blog. But today, after three early hours dodging the showers at the Show, I headed off to Wisley to dodge the torrential showers rather less successfully judging some of the flower trials.

    Begonia 'Bonfire'. Image: GardenPhotos.comA dozen judges plus our cheerful and efficient secretary, with umbrellas and raincoats in varying states of efficiency, spent the day looking at kniphofias, begonias for containers, amaranthus, alstroemerias, cortaderias, and Triphylla fuchsias. You can tell from that range of plants that there's some exceptional plantspeople on the committee. And there was one plant that stood out from the hundreds we looked at - and amongst the kniphofias and the cortaderias in particular there were some real stars.

    But one hanging basket of Begonia ‘Bonfire' was absolutely stunning.

    There are two main types amongst these begonias for containers: there are the familiar big and blowsy double flowered types - and in recent years these have been joined by a new range of more elegant varieties derived from B. boliviensis and ‘Bonfire' looks to be the best of these


  • Top wisterias in the trials

    Graham Rice on 30 Jun 2009 at 04:17 PM

    Wisteria sinensis 'Amethyst' on trial at Witch Hazel Nursery. Image: ©Wendy Wesley/RHS Trials OfficePlenty of shrubs and climbers have been at their peak recently including wisterias, honeysuckles, lilacs, Berberis, as well as the less well known Indigofera, Desmodium and Lespedeza, and the panel that assesses these plants have been busy.

    The wisterias were assessed at two sites near Wisley, Witch Hazel Nursery which houses one of the two National Collections, and the garden at Pyrford Court which is not open to the public. The plants have been growing for six or seven years now, this is the second year of assessment and some plants are emerging as likely AGM candidates.

    One interesting observation, which will help all of us identify mystery plants in our own gardens, was that W. sinensis, W. brachybotrys and the majority of American varieties twine in an anti-clockwise direction whilst W. floribunda and its hybrids twine clockwise.

    Amongst those rated most highly by the assessors was W. sinensis ‘Amethyst, which had developed relatively little leaf at flowering time and so showed its flowers more effectively than many. Its scent was also stronger than others and it was also noted that unpruned shoots flowered later than pruned shoots to extend the flowering season.

    W. sinensis ‘Prolific', noted as one of the most reliable, while W. brachybotrys was praised as the longest flowering of all and featured coppery young foliage.

    Wisteria brachybotrys 'Showa-beni' at Witch Hazel Nursery. Image: ©Wendy Wesley/RHS Trials OfficeThe pink flowered W. floribunda ‘Hon-beni' seemed on course to retain the AGM it received in 1993 although the best pink for colour was considered to be W. brachybotrys 'Showa-beni' but this had not flowered well last year so, at present, is not considered to be of AGM standard.

    Wisteria x formosa, a cross between W. floribunda ‘Alba' and W. sinensis raised in America more than a hundred years ago, was especially prolific


  • Sparkling berberis

    Graham Rice on 24 Jun 2009 at 04:09 PM

    Berberis thunbergii trial at the RHS Garden at Wisley. Image: GardenPhotos.comPlenty of shrubs and climbers on trial have been at their peak recently and the trial of Berberis thunbergii has been consistently colourful. These may not be the most fashionable of plants, but whenever I've looked at the trial I've been impressed by the variety of forms and the wonderful foliage colour.

    The trial is being held at Deer's Farm in Wisley village, an area only open to the public on special open days. The best of the seventy entries are becoming clear and these are proving to be a mixture of both uncommon and familiar varieties.

    Berberis thunbergii 'Clairon Rouge' at the RHS Garden at Wisley. Image: GardenPhotos.comAmongst those rarely seen ‘Boum', a seedling from France, slowly develops a rounded habit, with foliage in a striking blend of red, pink and white and was reckoned to be the best of the silver variegated types while ‘Clairon Rouge' (see image, left - click to enlarge) is a spectacularly fiery colour and would make stunning hedge. Originating in the Czech Republic, ‘Fireball' was praised for its stunning, neat, bright red leaves. ‘Orange Rocket' was impressive in its many shades of red and orange while ‘Rosy Rocket' had the tightest, most formal habit.

    Neither ‘Clairon Rouge' nor ‘Fireball' is eligible for an Award of Garden Merit at present as neither is available to gardeners. Availability is an important requirement for AGM plants - what's the point of giving a plant an award for its value in the garden if gardeners can't buy it?

    Of those which are more widely available, four stood out. ‘Admiration' has slowly become more impressive as the trial has gone on, its yellow-edged purple leaves turn crimson in the autumn. ‘Dart's Red Lady' has deep purple foliage which turns brilliant red in the autumn and ‘Harlequin' makes an upright, compact plant with relatively small leaves patterned in purple, pink and white.

    A number of different plants were entered as ‘Pink Queen' and while one was considered to be excellent and the most pink of the variegated entries, it's identity is still being confirmed.

    This is the last year of the trial, and there'll be Open Days on 15 and 29 July when you can go and see the Berberis as well as the honeysuckles and the abelias. The award winners will probably be announced in the winter.



  • Pinks Open Day and more...

    Graham Rice on 16 Jun 2009 at 01:44 PM

    Dianthus Tickled Pink ('Devon PP11') in the RHS Wisley pinks trial. Image: ©Sue Drew/RHS Trials OfficeThe forecast looks just right for the Pinks and Carnations Open Day at Wisley tomorrow. It can be uncomfortably scorching down on the trials field in the summer sun so tomorrow's forecast of cool conditions is ideal.

    The day starts at 11.30am when you can visit the trials of pinks - that's both traditional garden pinks and the miniature and dwarf pinks like ‘Tickled Pink' (in the picture). Members of the grandly titled Border Carnations and Pinks Trials Assessment Panel (that's the judges) will be on hand to talk about the trials and how it all works. You can ask them about the plants and how to grow them - it's a great opportunity to pick the brains of the experts.

    Then starting at 1.30pm there are three short talks by experts up at the Hillside Events Centre. Sue Hoy will be talking about Perfect Pinks, and demonstrating how to take cuttings; Mark Trenear will be discussing the fascinating history of pinks; while Ivor Mace will be outlining how to grow perpetual flowering carnations.

    Not only that, but the British National Carnation Society show will be taking place so you'll be able to see a wide range of perfect blooms - always inspiring - and Allwoods will have plants for sale so you can take away some plants for your own garden. It all happens tomorrow at the Hillside Events Centre near where the old glasshouse used to be  - just follow the signs. And once you're in the garden - it's free.

    Delphiniums at the RHS Wisley trial. Image: ©Ali Cundy/RHS Trials OfficeOf course there's plenty more to see on the trials field in June, this can often be the peak month of the summer. There's delphiniums, sweet peas, the annual climbers, the snap peas, the clematis, the begonias in containers and many more trials. Take the opportunity to make a note of the varieties that you find especially appealing.


  • Dwarf pinks trial - and Pinks and Carnations Open Day

    Graham Rice on 10 Jun 2009 at 05:06 PM

    Dianthus 'India Star'. Image: ©GardenPhotos.comThe dwarf pinks are coming into their peak now and the scent and colour is just captivating. But it was intriguing seeing the dwarf pinks a week or so back as they were getting into their stride. We expect pinks to flower all summer these days but exactly how they go about it makes a big difference to their impact.

    I noticed that some, like ‘India Star', ‘Red Star' (both of which already have AGMs) and ‘Starburst' simply produce new flowers just above the old ones - they look great. But others produce a flush of flowers all on one level, then the next crop of flowering shoots grows through them to come into bud 15-23cm/6-9in higher while the first flowers are still colourful - ruining the display. These included ‘Stardust', ‘Passion', ‘Slap ‘n' Tickle', ‘Sugar Plum', ‘Tickled Pink', ‘Show Girl' and ‘Romance'.Dianthus 'Show Girl'. Image: ©

    Over the rest of the summer it‘ll be interesting to see how these characteristics develop amongst the twenty three entries to the trial. And there's a also a trial of almost fifty more traditional garden pinks so don't miss those.

    And coming up soon is a great opportunity to talk to the experts about these invaluable plants. The Carnation and Pinks Open Day will be held at Wisley on Thursday 17 June 2009 to coincide with the second day of the British National Carnation Society Show in the Hillside Events Centre at Wisley.Dwarf pinks trial at the RHS Garden at Wisley. Image: ©Sue Drew/RHS Trials Office

    In the morning discuss the trials with membrs of the assessment panel down on the trials field, then in the afternoon listent to three talks by experts on pinks and carnations. And there's the show and Allwoods will be there with plants for sale. Sounds like a great day - and it's free! Just turn up.

    And for those of you can't get to Wisley, most of the plants in these trials are also being grown at East Ruston Old Vicarage Garden in Norfolk.


  • The season's first sweet peas

    Graham Rice on 05 Jun 2009 at 08:39 PM

    Sweet pea 'Aunt Jane'. Image: ©GardenPhotos.comI love sweet peas, in fact I like them so much I wrote a whole book about them, and I'm always eager for the first ones to come into flower. Picking the first few stems for the house is always a sign that summer is really here.

    So I was pleased to be able to look over the sweet pea trial at Wisley just as the first varieties were coming into flower and to make a note of those that produce the first stems for picking. Out of grand total of sixty two varieties in the trial, these were the first to produce at least one stem suitable for cutting. ‘Aunt Jane', a pale magenta from Dave Matthewman; ‘Toby Robinson', from Kerton Sweet Peas, in white with purple veining and already an AGM winner and ‘Gerry Cullinan', also from Kerton Sweet Peas, a lavender which was a star last year. Three as yet unnamed entries to the trial, two from National Collection holder Roger Parsons (who has 950 varieties in his collection!) were also pickable.

    It'll be interesting to see if these varieties also finish flowering early or if they have the staying power to last as long as the rest.

    Also just getting going down on the trials field are some relatives of the sweet peas amongst the one hundred and thirty two varieties being grown in the most extensive trial of annual climbers ever seen. There's a number of other annual climbing species and varieties of Lathyrus, a group of plants which is undeservedly passed as everyone focuses on the sweet peas, and sixteen of these are included.

    Lathyrus clymenum 'Articulatus'. Image: ©Ailson Cundy/RHSAmongst the first of these to open were Lathyrus clymenum 'Articulatus', with attractive bicoloured red and white flowers and the shorter but sparkling blue Lathyrus sativus 'Azureus'. Neither are as valuable as cut flowers as the familiar sweet peas but scrambling through low shrubs, especially when sown in the autumn in Mediterranean style gardens, they can really add a naturalistic look to the garden.

    The sweet pea trial will be well worth looking at for the nest few weeks, while the many lovely annual climbers on display will be worth a look right through till the autumn.


  • Ornamental rhubarb - send us your pictures

    Graham Rice on 01 Jun 2009 at 10:01 PM

    Rheum trial RHS. Image: GardenPhotos.comThe ornamental rhubarbs, Rheum, are dramatic flowering and foliage plants making bold specimens with, at their best, a very long season of interest. You can help the Herbaceous Plant Committee of RHS with our research on these plants.

    After the trial of ornamental rhubarbs ended in 2006 the plants were moved for further assessment and we took a look at them a few days ago. Frankly, they're a bit of a muddle. It's not as if there's a huge number of them, most of the rheums listed in the RHS Plant Finder are culinary rhubarbs. The problem is that they've become so mixed up that when you buy a plant under a familiar or promising name you've little idea of what you're actually going to get. It was clear that many of the plants we assessed were wrongly named and some good plants were not represented.

    These plants have five good features: the unfolding spring foliage can be very colourful, often dark red; the mature leaves can be impressive too, especially if they retain their red colouring on the upper surface and have an attractive shape; the flowering heads can be bold and colourful; the seed heads can also be impressive; and the whole plant can make a fine and imposing specimen.

    So we'd like you to send us pictures of really good ornamental rhubarbs. If you have plants which are especially impressive in one, some or all of these ways - please send me a picture. Tell me the plant's name, where you got it and when you got it and it will help the Herbaceous Plant Committee of the RHS understand the range of plants which are actually being grown around the country - and under what names. Please don't send plants! Just email pictures.

    Thank you! I'll report back here as we continue the research.



  • Alpines, clematis and peas on the trials this week

    Graham Rice on 29 May 2009 at 08:57 PM

    Roscoea cautleyoides 'Early Form'. Image: GardenPhotos.comLots to see on the trials field at the RHS Garden at Wisley at the moment. I was judging perennials on Tuesday and took the opportunity to take a look at all the other trials on the Portsmouth Field at Wisley.

    Alongside the bergenias at the bottom of the Portsmouth Field is the trial of Roscoea. Recently moved from a private area near the Alpine House, these are  hardy perennial Asian woodlanders with orchid-like flowers and one very obvious feature was apparent. Some plants were in full flower while others were just emerging.

    In full flower and looking very impressive was R. cautleyoides ‘Early Form', it was the most colourful of all the plants in the trial and was not only making fat clumps but spreading at the root.Roscoea cautleyoides 'Early Form', spreading quickly. Image:

    At the other extreme ‘Beesiana' and R. scillifolia were just emerging. This is actually rather a good thing, it proves that roscoeas can be colourful in late spring with other spring woodland flowers and also in summer when the spring woodlanders have faded.

    At the same end of the field, though a little higher up, the trial of Clematis in the Viticella Group was romping away. These are clematis derived, at lest I part, from the late flowering C. viticella which is pruned hard in spring for a late display. Another trial newly moved from less public area, some of the plants had already romped to the tops of their 2.1m/7ft supports and now shoots wave in the air by 60cm/2ft beyond. These included ‘Royal Velours', ‘Jorma', and ‘Södertälje' which are clearly the ones to choose if need a really vigorous plant.

    A friend had just been remarking that her snap peas produced so few tendrils that they had to be tied in so I took a look at the trial. It's true, some had relatively few tendrils and were not self supporting, the trials staff had used soft twine to stop them falling over. One variety, though, produced far more tendrils than any other the others and that was ‘Sugar Lace'. The interesting thing about this is that you can cook pea tendrils. You can sauté them, or cook them with mushrooms and finely chopped leeks.

    Three pea varieties had already begun to flower, an indication of those which will be the first to crop and these were ‘Sugar Ann', ‘Sugar Bon and ‘Norli'.

    Sempervivums on the roof of the Trials Field shelter. Image: GardenPhotos.comFinally, if you take a look at the shelter in the left hand corner as you come down the steps to the trials field - you'll see the sempervivums from the recent trial settling down well on the roof.


  • After the downpour at Wisley - Iris and Kniphofia

    Graham Rice on 26 May 2009 at 10:28 PM

    RHS Tall Bearded Iris trial. Image: ©GardenPhotos.comArrived at Wisley for today's trials assessment session soon after the thunderous downpour - and just look these irises!

    This is the Tall Bearded Iris trial just an hour or two after the torrential rain early this morning. Every flower was still beaded with rain drops and yet - they look spectacular. As soon you start to walk down the steps towards the Portsmouth Field at Wisley where the trials are planted - they just leap out at you. My advice: get down there and see them, make a note of the ones you especially like and check in the RHS Plant Finder which nurseries list them.

    Now - notice that plant at the back? You can hardly miss it. That's the best early flowering Kniphofia (red hot poker) by a million miles - Kniphofia ‘Atlanta'. Today it was genuinely spectacular and was a real star of the Kniphofia trial.

    Kniphofia 'Atlanta'. Image: ©GardenPhotos.comTurns out another branch of the RHS is looking into the origins of Kniphofia ‘Atlanta' and Dr Christopher Whitehouse is leading the investigation: "We know that Neil Treseder of the famous Treseder's Nursery in Truro found it growing in the garden of the Atlanta Hotel in Tintagel in 1962. However, we believe that it was obtained from a Surrey garden 10 years previously where it probably grew under another name.  Although the Atlanta Hotel has been re-developed and Treseder's closed down many years ago, to resolve this conundrum we're looking to find other plants that may have originated from the Atlanta Hotel in the Tintagel area. We'd like people to send photographs of their May-flowering Kniphofia to to help us in our quest."

    Got that? Please, send any photographs of your May-flowering Kniphofia to and please be sure to give the name you have for it and where you obtained it.

    Thank you!

  • AGM update – and sempervivums

    Graham Rice on 16 May 2009 at 01:13 PM

    Sempervivum calcareum 'Sir William Lawrence'. Image: ©GardenPhotos.comHere we bring you lots of early news of the plants which have been awarded the much prized RHS Award of Garden Merit or done well in the trials. Six months ago a full list of the plants awarded the AGM in the previous year was published, new on the scene is a list of plants which have received an AGM more recently.

    Some have already been covered here, but over the next few weeks I'll be looking at the others as well as checking in on the current trials.

    For three years the trials field at Wisley was home to over three hundred sempervivums - houseleeks. These neat, sun-loving, drought tolerant little plants are enjoying something of a revival, in part because this trial revealed their vast variety, how easy they are to grow and how good they look against a gravel mulch.

    Regular assessments over the three years of the trial narrowed the choice of the best to seventeen (plus one only suited to growing in the Alpine House. You'll find them listed in the May 2009 supplement to the AGM list.

    Sempervivum 'Delta'. Image: ©GardenPhotos.comSome of the AGM winners are old favourites like S. calcareum ‘Sir William Lawrence' which I especially liked for its tight and even clusters of prettily coloured rosettes (see first picture) and the deep red ‘Othello' while lesser known varieties like the olive green and red ‘Delta' (second picture) and ‘Spider's Lair' with small, rounded heavily webbed rosettes were also honoured.

    Grow these sempervivums as specimens in small pots or terracotta troughs, in larger troughs, as green roofs, in raised beds, on rock gardens, at the edges of gravel drives and as slowly spreading ground cover on poor soils. Just give them sun and good drainage.

    See the May 2009 AGM supplement to the AGM list

    RHS Plant Finder nurseries list the sempervivums I've mentioned, click the name for sources:
    Sempervivum calcareum ‘Sir William Lawrence'
    Sempervivum ‘Delta'
    Sempervivum ‘Othello'
    Sempervivum ‘Spider's Lair'


  • Bergenias - flowers and foliage

    Graham Rice on 12 May 2009 at 12:16 PM

    Bergenia 'Pink Dragonfly'. Image ©Terra Nova NurseriesI've mentioned the bergenia trial a few times here, it's been one of the most interesting perennial trials of recent years. And at a recent assessment session plantsman and retired nurseryman Chris Sanders suggested that however good its flowers might be, no bergenia should be given an Award of Garden Merit unless it also excelled as a foliage plant. We don't insist on that for, say, hellebores or delphiniums so what's so special about bergenias?

    The point is that bergenia flowers are often damaged by frost - they certainly were this year - so he felt it was unwise to give awards solely for flowers which in some seasons might not provide much of a display at all. Seems fair to me.

    Bergenia 'Glasnevin'. Image: RHS Trials Office/Alison CundyAnd the reverse is also true. As this last winter revealed, the foliage of most bergenias is very tough and can take a great deal of frost and snow so varieties with good foliage should get awards even if the flowers are less impressive. Frankly, if a bergenia has foliage which is sufficiently attractive right through the winter it wouldn't matter to me if it never flowered at all.

    So ‘Glasnevin', for example, had poor flowers which did not open properly but after the snow in February its foliage was very impressive (see picture). While  ‘Beethoven' and ‘Britten', both raised by the great British plant breeder Eric Smith, along with ‘Pink Dragonfly' (see first picture), were unremarkable in foliage but can be very impressive in flower.

    It will be interesting to how the assessors as a whole feel about this issue - all will be revealed when the awards are finalised


  • Carnation growing - up to date

    Graham Rice on 06 May 2009 at 10:26 PM

    Spray carnation 'Coquette'. Image ©Sue Drew/RHS Trials OfficeThe Wisley trials not only bring awards to the best plants, they also test new ways of growing them.

    In recent years only dedicated specialists (and mass market cut flower growers) have grown perpetual flowering carnations but a new approach has recently been investigated at Wisley, a way in which more of us can grow these exquisitely coloured and superbly scented plants without keeping them permanently in the greenhouse as is so often considered necessary.

    In fact, they can be grown in containers on the patio and two varieties of spray carnations, which are naturally branching and so ideal for this approach, stood out when grown in this way.

    In February, five plants were potted into 10 litre pots of peat free compost. The plant in the centre was left to grow naturally while the four plants set around the edge were pinched back when they had seven or eight pairs of leaves. This pinching encouraged bushy growth on more compact plants and created a more elegant display which was taller in the centre. Discreet support was put in place towards the end of April, and half the stems on the outer plants were again pinched at the end of May.

    Spray carnation 'Coquette'. Image ©Sue Drew/RHS Trials OfficeDuring all these preliminary stages the plants were kept in the greenhouse, with just enough heat to prevent frost; it would interesting to see how they perform with no heat at all. The judging panel noted that they are able to take low temperatures so it would be worth looking at.


  • Dazzling delphinium from seed

    Graham Rice on 24 Apr 2009 at 09:32 PM

    Delphinium 'Sweethearts'. Image ©Terry Dowdeswell/New Millennium DelphiniumsThousands of miles away on the other side of the world, near the shores of North Island New Zealand, Terry Dowdeswell who runs New Millennium Delphiniums is working away producing superb new varieties. He's the finest delphinium breeder in the world and we saw some of his plants in last year's trial of delphiniums from seed at Wisley.

    And that's the key: "delphiniums from seed". The RHS, in conjunction with the Delphinium Society, runs a permanent trial of traditional delphiniums, raised from cuttings. The finest varieties in the world are of this type. The problem is that plants produce so few cuttings for propagation that most gardeners never get the chance to grow them. It's just not possible for nurseries to produce enough plants.

    Terry Dowdeswell, over there in the foothills above Wanganui New Zealand, produces varieties which are intended to be raised from seed. By diligent hand pollination of specifically chosen parent plants he produces a wide range of varieties in a fantastic range of colours ensuring that variations in colour and quality are eliminated so you can really depend on the results. One of his varieties was awarded an Award of Garden Merit at last year's trial and seed is now becoming easy to buy.

    ‘Sweethearts' is such a gorgeous colour, as you can see from the pictures. And one of the particular features the trials assessors picked out, which is also obvious, was the "bloom architecture". That is, the elegance, the shapeliness and evenness of the spike of flowers and the way in which the flowers are held - after all, that's what determines whether a delphinium spike looks good or it doesn't. ‘Sweethearts' is one of the best of its kind.

    You can order seed of Delphinium ‘Sweethearts' from New Millennium Delphiniums or from Jelitto Seeds or from D'Arcy and Everest. And check out the New Millennium Delphiniums website and take a look all the other impressive Terry Dowdeswell delphiniums.



  • Bergenias in a frost pocket

    Graham Rice on 15 Apr 2009 at 05:49 PM

    Bergenia 'Reitheim'Looking over the Wisley bergenia trial two or three times recently, an unfortunate conundrum emerges. If the flowers stand up well above the foliage so they show themselves off to the full, with a chance to really enliven the spring garden - they get frosted. If they open on shorter stems, down amongst the foliage, they're protected from the frost but they may be so hidden that their value is lost. So what's the answer?

    Well, most important, don't plant them in a frost pocket. The bergenia trial is planted at the very bottom of the field so the cold air flows down the gentle slope and then the boundary hedge between the trials field and the busy A3 ensures that the icy air comes to a stop right where the bergenias are planted. It's probably the coldest place on the field, many of the bergenias have suffered while in other parts of the garden the same varieties often look rather better.

    Planting in such a cold place would be an excellent way of determining which varieties can best cope with a cold snap - if it wasn't for the fact that the flowers on so many varieties were damaged.

    But for me one variety, ‘Reitheim', stood out. It held its flowers partly amongst the foliage, which seemed to provide enough protection to prevent damage, but sufficiently visible to make a show. Other varieties which seemed less prone to frost damage or were so prolific as to look good in spite of being frosted include ‘Eroica', ‘Frau Holle', ‘Beethoven' and ‘Apple Court White'. ‘Morgenrote', which held an Award of Garden Merit prior to the trial, has been disappointing


  • Leeks to fill a hungry gap

    Graham Rice on 09 Apr 2009 at 10:13 PM

    Leek 'Bandit'. Image: ©GardenPhotos.comAs winter gives way to spring, fresh vegetables are in short supply. But leeks can fill that hungry gap. The current trial of leeks, now coming to a close, focuses on varieties that stand the winter and are still in great shape for cutting in March and April.

    The assessment panel have been looking them over for a while now, checking for disease and making sure the entries are true to type. They noted that keeping the crop well fed and growing on, especially during September and October when the mornings are dewy, helps the plants to resist rust. I've taken a look at them myself twice in the last couple of weeks and, apart from noticing some rot, other features struck me.

    Firstly, the colour varies quite noticeably between varieties. Some were very green in colour while others, especially ‘Triton', were so blue that they'd make good ornamental foliage plants! ‘Snowdon', on the other hand, was very green.

    Leek 'Triton'. Image: ©GardenPhotos.comI also noticed that even within individual varieties there was unexpected variation. A few individual plants showed an attractive purple tint; in many the height varied along the rows and the diameter of the individual leeks also varied. Jacquie Gray, from the Trials Office staff, who was measuring the sizes of each variety while I was there, was having trouble measuring some varieties because they varied so much.

    The committee noted, and it was clear looking at them, that the old favourite ‘Musselborough' has become so variable that growing it really is a gamble, you just don't know what you're going to get so it's best to grow one of the more dependable varieties. They also pointed out that some good varieties like ‘Toledo', ‘Longbow' and ‘Apollo' were valuable earlier but deteriorated and were not good for a late crop. Another thing they looked at, which is not immediately apparent, is the extent to which the flower stem was growing up through the leek. Many people feel this spoils the eating quality

    So... the most promising entries for this late season gap, in addition to some as yet unnamed varieties from British vegetable breeder A L Tozer, were ‘Bandit', ‘Atlanta' and ‘Edison'.

    Order ‘Bandit' from E. W. King
    Order ‘Atlanta' from D. T. Brown
    Order ‘Edison' from Marshalls Seeds


  • Last year’s marvellous marigolds

    Graham Rice on 03 Apr 2009 at 06:16 PM

    Afro-French marigold 'Zenith Yellow'. Image: FloranovaLast summer was not really an ideal one for French marigolds so those that did well in the Wisley trial really must be good. There were 132 in the trial altogether - both French marigolds and Afro-French hybrid marigolds and this week the eight that were especially outstanding had their Awards of Garden Merit ratified.

    Afro-French hybrid marigolds, I should explain, are exactly what the name suggests: hybrids between African and French marigolds. They make larger plants than most French marigolds, some of which are so small as to be hardly worth growing, they're very bushy, and they have single or double flowers much smaller than those of African marigolds. And unlike most marigolds, they're bred in Britain so are well adapted to our climate. I thought they were superb in last year's wet summer.

    French marigold 'Bonanza Flame'. Image: Ball SeedFive French marigolds were awarded AGMs. ‘Aton Yellow' with its slightly anemone-centred lemon yellow flowers set against dark foliage and its gold sister ‘Aton Gold' were excellent. ‘Pascal Rusty' had striking picotee flowers while the single-flowered ‘Disco Orange' was very uniform and very bright, with the new flowers hiding the old ones - always a valuable feature. ‘Bonanza Flame', in rusty orange with a yellow edge to each petal, carried especially long lasting crested blooms which also hid the fading flowers.

    When I assessed the marigolds as part of the judging panel it was the Afro-French hybrids that impressed me most. They're incredibly prolific with a very very long season and almost without exception the new flowers open just above the old ones - they never need dead-heading. Three received awards, two doubles and one single; personally I'd probably have given one or two more.

    Afro-French marigold 'Sunburst Yellow Splash'. Image: FloranovaThe two doubles, ‘Zenith Golden Yellow' and ‘Zenith Yellow' had incredible impact while the single ‘Sunburst Yellow Splash', with each yellow petal splashed in red, was notable in that the individual flowers stood up especially well to the rain.

    And the ratification of these awards is very timely... These marigolds grow so quickly once they germinate that April is good time to sow them. And my personal advice is to try any Zenith and Sunburst varieties you can find.


  • Daffodils at their peak

    Graham Rice on 29 Mar 2009 at 04:29 PM

    Narcissus 'Patrick Hackett'. Image: ©Sue Drew/RHS Trials OfficeMany of the trials at Wisley are composed of two parts: the trial of all the varieties in contention for an Award of Garden Merit and, alongside, a demonstration and those which already hold the award. So visitors not only get to see all the newcomers but also those whose standard they have to reach. And the result is a colourful collection of intriguing varieties - and now's the time to see them. Take note of those you like ready to order for planting in the autumn.

    The assessment panel has been looking over the plants since long before they started flowering, keeping their eyes open for disease problems, but now that flowering is well under way a number of the new entries have proved especially impressive.



  • Late cauliflowers

    Graham Rice on 22 Mar 2009 at 02:17 PM

    Assessing the RHS cauliflower trial. Image: ©RHS Trials Office.Cauliflowers are not the easiest vegetable to grow but they are amongst the relatively few vegetables that can be grown to cut in late autumn and winter. And fresh food from the garden at that time of year is always a treat so this cauliflower trial, recently ended, was especially useful.

    Twenty eight varieties were sown, including some with coloured heads, and it was the quality of the heads that was the most important factor in the judges' assessment. Quality is made up of a number of factors including colour, smoothness, uniformity, the depth of the curd and how well the foliage folds over the head as protection against winter weather.Cauliflower 'Belot'. Image: ©Clause Teziér.

    It was a difficult winter, exceptionally cold at times, but although the heads froze sometimes solid the crop was largely undamaged. Cutting on frost-free days was recommended. All the seed was sown inside at 15-20C  in mid June and the young plants set out in late July.Cauliflower 'Triomphant'. Image: RHS Trials Office..

    Four varieties were recommended to receive the Award of Garden Merit.
    'Belot', at its peak in January, and ‘Deakin', at its best in November, both produced a good crop of solid white curds well protected by their foliage.  ‘Regata', at its best in November, was vigorous and especially useful for home gardeners as it tended to produce side shoots as well as heads of good quality. The January cropping ‘Triomphant' made large plants with well protected heads that, while smaller than many, were unusually deep and solid.

    No varieties with coloured heads received awards but one of the assessment panel, Paul Corfield of vegetable breeders Clause Teziér Seeds, reported that they had developed some good late cropping green-headed Romanesco types but they were not being released. "They damage too easily in transport to appeal to supermarkets," he said, "and with the only interest coming from the retail seed companies for home gardeners, this was unlikely to provide large enough volume of seed sales to make the varieties commercially viable."

    Please add a comment below if you'd like to see these released - perhaps they can be persuaded!

    Seed of cauliflower 'Belot' is available from The Organic Gardening Catalogue

    Young plants of cauliflower 'Belot' are available from Vegetable Plants Direct

    Young plants of cauliflower ‘Deakin' are available from Gardening Direct and from Vegetable Plants Direct Read More...

  • Crocus vote

    Graham Rice on 14 Mar 2009 at 01:53 PM

    Crocus 'Jeanne d'Arc'. Image: ©GardenPhotos.comAs the mild weather brings the crocus season to a close, I can bring you the results of the visitors' vote for their favourite in the Wisley crocus trial. For a couple of years the trial was grown in the Alpine Department where there is, unfortunately, limited access for visitors. So, for its final year, it was replanted on the trials field where visitors could take a look at any time.

    To be honest, I was disappointed at the number of votes cast - this is such a great opportunity for visitors to have their say it was a shame that more didn't make the most of it.

    And then, after all that, it turned out that the top two in the voting were rather problematical choices. Top in the voting came the pure white ‘Jeanne d'Arc'. As some of the visitors described it in their comments: "A beautiful strong-looking white. Lovely!", "Stunning" and "Not only looks great but the bees loved this one the best which adds to the interest and beauty".

    The problem was that Dutch Hybrids like ‘Jeanne d'Arc' were not supposed to have been included in the trial - it was supposed to have been restricted to species! I'm sure the visitors' vote will be kept in mind when all the Dutch Hybrid crocus are trialled side-by-side but this time it's unlikely to get an award as it wasn't compared with similar types.

    Crocus 'Margot'. Image: ©GardenPhotos.comAnd although the second in the voting, the lovely bicoloured purple ‘Margot', has been known for almost a hundred years it's now so rare that, according to the RHS Plant Finder, no nurseries sell it! And that's a shame as visitors found it especially appealing - "Lovely double colours", "Lovely colour" and "Nice contrast of purples". It was one of my favourites too. The third in the voting, ‘Little Amber' (rich amber yellow, with brown tiger-stripes on the outside petals), also goes unlisted by nurseries.

    But this illustrates another great virtue of these trials. When neglected varieties like ‘Margot' and ‘Little Amber' perform so well and are so appreciated by visitors - it's a great encouragement for nurseries to list them.

    Bulb nurseries: please let me know if you're adding these two varieties to your catalogues.


  • Carnation and garden chrysanths awarded AGM

    Graham Rice on 06 Mar 2009 at 12:18 PM

    Carnation 'Spinfield Charm'. Image: RHS Trials OfficeTrials of outdoor carnations and chrysanthemums take place every year at Wisley. It's a long standing tradition and even after so many years fine new varieties are still being recognised and receiving the Award of Garden Merit. The latest awards have just been confirmed.

    Although attracting a fervent following amongst specialists, most gardeners do not yet realise what wonderful plants border carnations are. Their colouring, pattering and fragrance are outstanding and they're not difficult to grow given sun and well-drained soil. The only problem is that they always need support - but their gorgeous flowers are well worth a little effort.

    ‘Spinfield Charm' looks to be a step in the right direction for most of us as the judges described it as being sturdy with an erect habit. They admired the flowers too, which they described as having "good form and a lovely colour which does not fade" and all set off by "wonderful grey foliage". As soon as some enterprising nursery offers it for sale its AGM can be confirmed.

    Described as "fantastic" by the expert carnation judges, ‘Spinfield Crimson' is already available. Its beautiful form, lovely rich red colouring and again its vigour set it apart.

    All the varieties with the Spinfield prefix are raised by Buckinghamshire's Peter Russell, former President of the British National Carnation Society. ‘Spinfield Lane' already has an award.

    Chrysanthemum 'Myss Marion'. Image: ©RHS Trials Office.Old fashioned spray chrysanthemums, like the traditional Koreans, are increasingly seen as valuable autumn perennials but modern spray chrysanths also pack a powerful floral punch. Two have recently had their awards confirmed, ‘Myss Saffron' and ‘Myss Marion'.

    ‘Myss Marion' is rich creamy yellow in the centre of each flower, shading to white at the edges, while ‘Myss Saffron' is a brilliant rich yellow with an amber centre in younger flowers. Both are prized for exhibition as well as the garden.

    You can order these new award winners now and grow them in your own garden.

    Order carnation ‘Spinfield Crimson' from Bofield Carnations

    Order Chrysanthemum ‘Myss Marion' from Halls of Heddon

  • Take part in an RHS trial - in your own garden

    Graham Rice on 05 Mar 2009 at 02:42 PM

    Sugarsnap pea 'Sugar Ann'. Image©Thompson & Morgan.This year the RHS is running a trial of sugarsnap and mangetout peas both at Wisley and at Rosemoor. And you can take part at home as well.

    The RHS is looking for 200 gardeners around the country to grow two varieties of peas and report on their experieces.

    Check out the online mangetout and sugarsnap pea trial webpage on the RHS website to find out how to take part.


  • Huge crops from climbing French beans

    Graham Rice on 26 Feb 2009 at 05:50 PM

    Climbing French bean trial. Image: Ali Cundy/RHS Trials OfficeClimbing French beans must be one of the top crops for yielding the most food, and the tastiest food, from the smallest space. But of course, it's not just about kilos on the scales - it's about flavour, table quality and how easy the plants are to grow. The recent trial revealed those that combined the best of all these qualities to gain the Award of Garden Merit.

    One important feature of this trial was that not only were the plants grown on the trials field at Wisley but, thanks to the generosity of Alan Gray and Graham Robeson, the whole trial was replicated at their garden at East Ruston in Norfolk. The results from both trials were collated to arrive at the final award winners. Nine varieties were given awards. 

    Climbing French bean 'Musica'. Image: Ali Cundy/RHS Trials OfficeThirty one different varieties were grown, round podded and flat podded, and all were sown in the open ground on 16 May, the above view of the trial was taken on the 8 July - less than two months later.

    Two flat podded types yielded the heaviest crop - ‘Musica' (976g per plant) and ‘Pantheon' (965g per plant).Two plants were grown up each leg of a four-legged wigwam so for each wigwam that gives 7.8kg/17lb 3oz for ‘Musica' and 7.7kg/17lb for ‘Pantheon'. That's a lot of beans from one wigwam. At that rate of production, how many wigwams does your family actually need? You see what I mean about impressive productivity for the area the plants actually occupy. The judges said that ‘Musica' was "flavoursome" and that ‘Pantheon' had a "sweet flavour".

    ‘Cobra' was the only round bean to gain an AGM while ‘Eva', with its oval pods, also gained an award


  • Bergenias after the snow

    Graham Rice on 25 Feb 2009 at 02:03 PM

    The icy and snowy weather earlier this month revealed one way in which the Wisley trials are so useful. One of the most valuable features of bergenias is their winter foliage colour and the recent weather has put them to the test - some retained their foliage and were revealed in glorious colour when the now melted. The foliage of others was reduced to pulp.

    Here's the bergenia trial under the snow...
    Bergenia trial under the snow. Image: RHS Trials Office/Alison Cundy

    Here it is a few days after the snow had melted. You can see that some are a fantastic bright red. Others are more dowdy, while there seem to be some gaps.
    Bergenia trial after the snow. Image: RHS Trials Office/Alison Cundy

    So here's Bergenia ‘Glasnevin' on the left, one of the most colourful - and on the right, Bergenia ciliata ‘Patricia Furness' with its foliage ruined. The judges will continue to assess them as they come into flower.
    Bergenia 'Glasnevin'. Image: RHS Trials Office/Alison Cundy Bergenia ciliata ‘Patricia Furness’. Image: RHS Trials Office/Alison Cundy


  • Hydrangea trial and bulletin

    Graham Rice on 30 Jan 2009 at 09:08 PM

    Hydrangea paniculata Trials Bulletin. Image: RHS Trials OfficeWhen I saw the Wisley trial of forty seven different forms of Hydrangea paniculata last September I was impressed.  These are easy and dependable summer and autumn shrubs whose shapely blooms provide attractive colour from bud to faded flower  And this week's publication of a free-to-download full colour bulletin on the trial reminds me what a wonderful sight they were.

    You may also have seen the well-established specimens on the walk up Battleston Hill from Wisley's double herbaceous border - they're stupendous.

    Hydrangea paniculata trial at Wisley. Image: ©Graham Rice/GardenPhotos.comBut until I saw the trial I'd not realised that some age far more harmoniously in colour than others.  The trial judges kept that in mind and plants were also judged for their habit, their response to pruning, for the colour of their buds, flowers and faded flowers and the shape of their flower heads, and for how their heads were held (upright or floppy); stem colour, and summer and autumn foliage colour were also assessed.  Ten proved worthy of  the Award of Garden Merit.

    But there was much more to this trial than simply judging the quality of the plants.  Two pruning trials were also carried out.

    There were three plants of each variety in the trial: one plant was pruned hard, one pruned moderately, and one simply dead-headed.  The treatments had a very noticeable effect on flowering time and flower size.  In the other pruning trial, additional plants were pruned either in February, March or April. This too influenced flowering time.

    Now, when a Wisley plant trial proves especially successful or especially interesting - as this one was - the enterprising staff of the Botany Department and the Trials Office get together, with input from the judges, to produce a report: a Plant  Bulletin.  There's a complete list of bulletins on the RHS website.  The 16 page, full colour Hydrangea paniculata bulletin is just out.

    Not only does it reveal and illustrate the results of those pruning trials but all 47 varieties are described and illustrated with AGM winners illustrated at two stages of their flowering season.  Packed with useful information, it's available as a FREE download. Read More...

  • Top dahlias

    Graham Rice on 29 Jan 2009 at 03:08 PM

    Dahlia 'Magenta Star'. Image: RHS Trials OfficeLast year the Wisley dahlia trial was one of the most colourful - and interesting - of the season. It usually is. It's always worth seeing just to admire the dazzling display. But of course there's a purpose to it: finding the best.

    Out of a grand total of one hundred and forty nine different dahlias, from The Netherlands as well as from all over Britain, just four were chosen as being good enough to receive an Award of Garden Merit (AGM). The awards have now been ratified and all four will be available to gardeners this year. And just to be clear, these are primarily garden dahlias, not show dahias, although AGM dahlias can be good for showing as well.

    Dahlia 'Mayan Pearl'. Image: RHS Trials OfficeOne of the striking things this year is that only one of the four award winners is a big traditional double dahlia - two are Collarettes and one is a single flowered variety.

    The judges were chaired by Jon Wheatley, a member of the Executive Council of the National Dahlia Society who also advises the National Dahlia Collection. "The four new AGMs this year are individually outstanding," he told me. "The single flowered ‘Magenta Star' with its dark foliage is a welcome addition to any garden. ‘Mayan Pearl' never stops flowering irrespective of the weather and ‘Trelyn Daisy', a pure white Collarette, is good for garden and exhibition . But the most interesting for 2009 is ‘Woodbridge', the first Dahlia to get an AGM for its foliage."


  • New trials blog

    admin on 27 Jan 2009 at 12:07 PM

    Wisley Trials in June. Image: Ali Cundy, RHS Trials OfficeThe current RHS Plant Finder lists over 70,000 different plants and there are vegetables and many more that never find their way into the book. But how do you know which are the best? Well, the RHS tests many of them at its garden at Wisley and gives the prestigious Award of Garden Merit to those few that outshine the others. And that's what this new blog is all about - the best plants, as proved at the RHS trials.

    Assessing the Wisley carrot trial. Image: Ali Cundy, RHS Trials OfficeI'll be bringing you news of the latest awards, highlighting the trials looking their best and noting the growing techniques which prove successful. The Wisley botanists sort out muddles in the names of the plants on trial, pest and disease problems are revealed, there are events at which you can meet the judges, bulletins and other publications appear during the season; I'll be posting about all that and more here. Sometimes AGM plants even have their awards taken away - I'll bring you that news too - as well as comments from the judges themselves.