Plenty 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.
Amongst 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.