Wisterias are woody deciduous climbers, which are native to the eastern states of North America, China and Japan.
They are cultivated for their showy, pea-like fragrant flowers, which are borne in pendant racemes in spring and summer. The flowers are occasionally followed by pendulous green seed pods.
W. brachybotrys. (Silky Wisteria) A Japanese variety with broad racemes of scented flowers which open early in the season, before the velvety leaves appear. There are white, pink and mauve cultivars. Popular varieties include ‘Showa Beni’ which is the pinkest wisteria.
W. floribunda. This hardy Japanese wisteria has the longest racemes of all the species, they can reach up to1m (3ft). This is the best variety to cover pergolas, the racemes are so long they do not always hang well when grown against a wall. Popular varieties include ‘Caroline’ (lavender-mauve), and ‘Macrobotrys Burford’ (pale lilac-blue).
W. frutescens. A rare American variety which has short racemes of scented lilac-flowers. It flowers from June to August so is later than other varieties and is also less vigorous, which means it is possible to grow it as a standard. Popular varieties include ‘Magnifica’ (lilac-blue).
W. sinensis. The Chinese variety flowers at an early age. It has shorter, fatter racemes than floribunda. The flowers are very scented and can be found in white and various shades of pink and mauve. Popular varieties include ‘Prolific’ (lilac).
It is possible to help identify an unknown plant by noting if the stems twine in a clockwise or anti-clockwise direction when viewed from above. If the stems twine in a clockwise direction the plant is a variety of floribunda. If they twine anti-clockwise it is a cultivar of sinensis, frutescens or brachybotrys.
An exception is brachybotrys ‘Murasaki Kapitan’ which is the only cultivar of this variety to twine in a clockwise direction.
If identifying a plant which twines anti-clockwise, frutescens can be identified due to having velvety leaves. Brachybotrys is identifiable by its tendency to flower later in the year with flowers lasting until August.
CULTIVATION: Wisterias can be trained to grow against a wall or over arches and pergolas where the flowers can hang freely.
Wisterias climb by twining around their support. The lower parts of the plant, which are growing vertically, do not flower. It is only when the stems have reached the top of their support that they fall to horizontal and start flowering. To achieve this in the garden they can be trained to grow along horizontal supports, these need to be 45-60cm 1.5-2 feet apart.
They are best planted in a well drained, not too fertile soil as too many nutrients will result in all leafy growth and no flowers. To produce the most flowers they require full sun, although they will tolerate some shade.
PRUNING: Prune all new shoots back to two or three leaves from the base of the new growth after flowering. This will encourage the development of short spurs on which many flower buds appear. Any drastic shaping or cutting back should also be carried out after flowering.
Light pruning can be carried out during the summer. In autumn, untidy or unwanted shoots can be removed to tidy the plant ready for flowering in the spring.
Every effort has been made to ensure the accuracy of the information given both on our lists and labels. However, some details may vary according to special or geographical circumstances. Varieties offered are subject to availability.