Trials and Awards

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

2010-05-21T18:56:00Z

‘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

2010-05-18T12:46:00Z

Well, 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.

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

2010-05-05T19:01:00Z

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.

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

2010-04-28T12:28:00Z

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

2010-04-26T17:21:00Z

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.

Daffodils on trial at Wisley

2010-04-18T09:30:00Z

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.

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 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

2010-04-13T14:54:00Z

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.

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

2010-03-31T12:28:00Z

For 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 trees
* 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

2010-03-27T14:12:00Z

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.

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

2010-03-23T11:47:00Z

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.

“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

2010-03-10T12:15:00Z

With 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.

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

2010-03-02T13:15:00Z

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.

Gold Medal winners in Wisley/Fleuroselect trial

2010-02-25T11:42:00Z

The 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.

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.

Smaller melons score well in a cloudy summer

2010-02-20T12:20:00Z

Some 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.

AGMs for hardy chrysanths

2010-02-10T13:59:00Z

In 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.”

‘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.