Common Name: Chinese Wisteria

General Information

Wisteria sinensis is a vigorous, deciduous climbing shrub capable of growing to the tops of tall trees and also scrambling sideways. The trunks of old plants can exceed 150cm in diameter[]. When given space, old specimens can spread laterally for 35 metres or more from each side of the main stem[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is often grown as an ornamental, valued especialy for its floral display in the late spring.
Wisteria sinensis is widely grown as an ornamental and has often escaped and become naturalized. It is considered to be a noxious weed in parts of the USA[].

Known Hazards

The seed of all members of this genus is poisonous[]. The bark contains a glycoside and a resin that are both poisonous[].
The seed and seedpod contain a resin and a glycoside called wisterin. Toxic in large quantities, causing nausea, vomitting, stomach pain and diarrhoea[]. Their consumption has caused the poisoning of children in many countries, producing mild to severe gastro-enteritis[, ].

Botanical References

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Range

E. Asia - southern and central China [Guangxi, Guizhou, Hebei, Henan, Hubei, Shaanxi, Yunnan]

Habitat

Clambering over cliffs and trees on woodland edges at low altitudes in W. China[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Climber
Height	20.00 m
Growth Rate	Fast
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Wisteria sinensis is moderately cold-hardy, tolerating temperatures down to around -15°c when fully dormant[, ]. 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[, ]. Succeeds in partial shade. Plants can become chlorotic on alkaline soils[]. A soil that is too rich results in excessive foliage at the expense of flowering[].
A widely grown ornamental, the plant s as remarkable for its rapid growth as for its wealth of blossom[]. There are several named forms selected for their ornamental value[].
Plants can take a few years to settle down after planting out[]. Too much shade or too rich a soil are normally the culprits, some form of root restriction can be beneficial[].
Sparrows and other birds frequently eat the young buds of this plant and this is the commonest cause of poor flowering on established plants[]. Plants sometimes have a second season of flowering in August[].
The plants flower mainly on short spurs so, if removing unwanted side-branches, it is best to cut them back to 2 - 3 leaves rather than removing them completely since this will encourage the formation of flowering spurs[]. Any drastic pruning is best carried out in the spring, immediately after flowering[]. Plants are very tolerant of even the most drastic pruning and will re-grow even if cut right back to the base[].
A climbing plant supporting itself by twining around other plants, the shoots twine in an anticlockwise direction[, ].
Very tolerant of pruning, plants can regenerate from old wood[].
Plants in this genus are notably susceptible to honey fungus[].
Closely related to W. floribunda[].
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[]. The plants also form a symbiotic relationship with a mycorrhizal fungus which makes more water, phosphorus and other minerals available to the plants[].

Edible Uses

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

Flowers - cooked. They are thoroughly washed and then boiled or made into fritters[, , , ]. The flowers are also cured in sugar then mixed with flour and made into a famous local delicacy called 'Teng Lo'[].

The leaves contain allantoic acid[]. They are used as a tea substitute[]. The young leaves have also been eaten[].

Medicinal

The seed is diuretic[, ]. It is used in the treatment of heart ailments[, ].

One report says that the stems and flowers are also used in Chinese medicine, but gives no more information[].

Other Uses

A fibre from the stems can be used to make paper, the fibre is about 1.3 - 3.7mm long[]. Stems are harvested in the summer, the leaves removed and the stems steamed until the fibre can be stripped. The fibres are cooked for 2 hours with lye and then put in a ball mill for 3 hours. The paper is a buff colour[].

An extract of the seeds has been used as an insecticide[].

An extract of the plant is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].

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[]. Germination should take place in the first spring, though it can sometimes be delayed for another 12 months. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a cold frame for their first winter. Plant them out in late spring or early summer. Plants are very slow from seed and can take up to 20 years to come into flower[].
Basal cuttings of side-shoots in early to mid summer in a frame[]. Take the cuttings as soon as the new growth has hardened sufficiently, each cutting should have 2 - 3 leaves[]. It can also help to remove a shallow slice of bark from the bottom 15mm of the cutting to expose extra cambium, since this will encourage more callusing and better rooting[]. When kept in a mist frame with a bottom heat of 27 - 30°c, they will root within 4 weeks and produce well-established plants by the autumn[].
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.
Division of suckers in the winter[]. If growing named varieties, it is of course necessary to ensure they are growing on their own roots if the suckers are to be true to type[].