Wisteria is another plant in the leguminous family. Its related to peas. Its perhaps not so surprising it has lovely fragrance. Leguminous plants can help to put nitrogen back into the soil through nodules on their roots.
Wisterias generally grown in the UK gardens are sinensis or syn. chinensis or floribunda. They come from China and floribunda from Japan, making them very hardy. Colours are white, blue, lavender or lilac and purple.
The Chinese tend to have a bigger flower (lots of flowers make up the dangly raceme) and grow anticlockwise which is apparently a little more unusual in the plant world and the Japanese are generally have longer racemes of flowers and grow more conventionally clockwise. Within these species there are quite a few variations in size and colour but all are fragrant.
Other species of wisteria are grown n the Uk. There is an early American species frutescens which has a really full chunky flower but is less hardy, so probably only suited to our milder areas. It flowers early before the leaves unfurl unlike our Asian species. There are also European hybrids of floribunda crossed with the highly fragrant brachybotrys another Japanese species with shorter racemes. Hybrids of W. sinensis and W. floribunda produce formosa varieties.
Growing Wisteria
The most common problem I see with a wisteria is planting it too close to a wall so it gets no moisture to the roots and doesn’t form flowers. Plant it a few feet away and direct its growth into the wall. If an area that never gets rained on, the dry side of the house, reconsider the position. I get no rain on the north east of my house due to the apex of my roof and therefore have a very dry bed, where I have successfully killed a hardy hydrangea (despite them being so suitable for a northerly position.) A lot of climbers are planted too close to a wall in very dry soil. Wisteras like moisture and sun and they take a little time to establish. Once establised they are quite prolific.
Pruning
Pruning
Prune your wisteria twice a year once you have a framework. Long whippy side branches with lots of flowers diminishing in size are a disappointment. We keep the wippy branches short. It is quality not quantity. Chop it to 2 or 3 buds in July after flowering and and do it again in about February.
Which to Choose
Some of our most popular varieties are: Wisteria sinensis Prolific (18m) often chosen for a big display on houses and W. formosa Caroline (6m by 5m). I think I am tempted by the floribunda multijuga with its exceptionaly long bi-coloured pale lilac\ violet racemes (6m by 5m) and f. Blackdragon (Kokyryu) with its long cascading flowers of deep purple and spicy perfume. (9m)
