Wisteria japonica

At a glance

Exposure: Full sun
Frost limit: −12.2 °C

Cultivation

Prefers a good loamy soil in a sunny south or south-west facing position, sheltered from cold winds and from early morning sun on frosty mornings. This species is not hardy in the colder areas of the country. There is some confusion over the correct name of this species, many authorities referring it to a separate genus as Millettia japonica (Sieb.&Zucc.)A.Gray.. Plants can take a few years to settle down after planting out. A climbing plant, attaching itself to branches or whatever by twining in a clockwise direction. Plants in this genus are notably susceptible to honey fungus. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.

Propagation

The seed does not exhibit any dormancy habits. It can be sown as soon as it is ripe in a cold frame and should germinate in the spring. Pre-soak stored seed for 24 hours in warm water and then sow in a greenhouse in early spring. The seed can also be sown in an outdoor seedbed in late spring. Basal cuttings of side-shoots in early to mid summer in a frame. Layering in spring. Simply lay any convenient long shoot along the ground and cover it with a shallow layer of soil. The shoot will readily produce roots at intervals along the stem. When these are well formed, the shoot can be divided up into a number of plants. These should be potted up and kept in a lightly shaded position in a greenhouse until well established and can then be planted out as required.

Edible uses

Seed - cooked. Some caution is advised, see the notes on toxicity at the top of the page. Young leaves - cooked.

Habitat

Clambering over cliffs and trees on woodland edges and in thickets in lowland, C. and S. Japan.

Native range

E. Asia - Japan, Korea.

Scientific synonyms Wisteriopsis japonica