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.