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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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  • 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.