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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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  • 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.