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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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Clematis trial is impressive

Posted by 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.



Digger said:

It's probably a good way to grow and display a large collection

on 27 Jul 2009 at 11:08 PM

Graham Rice said:

And it might also be a good way to grow varieties of this type as a feature in a crowded border.

on 28 Jul 2009 at 06:49 PM