Common Name: American Wisteria

General Information

Wisteria frutescens is a deciduous climbing shrub with slender, twining stems that can climb into nearby trees and shrubs and, if given the space, can spread 12 metres or more from each side of the main stem[].
The plant is harvested from the wild for local use as a food. It is grown as an ornamental, valued especially for its summer floral display.

Known Hazards

The seed of all members of this genus is poisonous[].The seed and seedpod contain a resin and a glycoside called wisterin. Toxic in large quantities, causing nausea, vomitting, stomach pain and diarrhoea[]

Botanical References

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Range

South-eastern N. America - Michigan to Massachusets, south to Texas and Virginia (probably naturalized in the north of this range)

Habitat

Clambering over cliffs and trees on woodland edges in low moist ground[, ].

Properties

Edibility Rating
Habit	Deciduous Climber
Height	12.00 m
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

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[, ]. Plants can become chlorotic on alkaline soils[]. A soil that is too rich results in excessive foliage at the expense of flowering[].
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[].
An attractive plant, often frown as an ornamental, a number of named forms have been selected for their ornamental value[].
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[].
Plants in this genus are notably susceptible to honey fungus[].
The stems of this species twine in an anticlockwise direction[].
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

The fresh flowers are eaten in tossed green salads[]. They are said to be excellent when dipped in batter and fried in oil as fritters[].

Medicinal

None known

Other Uses

None known

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.