Kudzu Vine (Pueraria montana lobata)

Other names Japanese arrowroot, Kudzu

At a glance

Lifecycle: Perennial (hardy)
Exposure: Full sun
Frost limit: −23.3 °C

Cultivation

Grows best on well-drained loam soil of good fertility. Plants are hardy to about -15°c, they can resprout from the base if they are cut down by frosts. This plant is cultivated for its edible root in Japan and China. The flowers have a sweet vanilla scent. When grown in warmer climates than Britain the root can be invasive and plants have become weeds. 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

Pre-soak the seed for 12 hours in warm water and sow in a warm greenhouse in early spring. Germination should take place within 2 weeks. Prick out the seedlings into individual pots when they are large enough to handle and plant them out after the last expected frosts. Cover the young plants with a frame or cloche until they are growing away well. Division of young shoots from the crown. The young shoots are removed in the spring with some of the underground part of the stem, preferably with some roots already formed. They are potted up and will usually develop new roots from the nodes. They are planted out in the summer if growth is sufficient, otherwise they are grown on in pots for a year and planted out late the following spring.

Edible uses

Root - cooked. A nutritional analysis for the whole root is available. Flowers - cooked or made into pickles. Stems and young leaves - raw or cooked.

Medicinal uses

The kudzu vine, known as Ge Gen in China, is commonly used in Chinese herbalism, where it is considered to be one of the 50 fundamental herbs. The flowers and the roots are antidote, antiemetic, antipyretic, antispasmodic, demulcent, diaphoretic, digestive, febrifuge, hypoglycaemic and hypotensive. The root contains puerarin. This increases the blood flow to the coronary artery and protects against acute myocardial ischaemia caused by the injection of pituitrin. The root can be harvested from the autumn to the spring and is used fresh or dried. The flowers are harvested just before they are fully open and are dried for later use. The stems are galactogogue and are also applied as a poultice to incipient boils, swellings, sore mouths etc. The seed is used in the treatment of hangover and dysentery. The leaves are styptic.

Material uses

A tough, strong fibre from the stems is used to make ropes, cables, coarse cordage and textiles. Can be used as a ground cover plant in a sunny position. Plants have an extensive root system which can be 1.8 metres deep, they are used for erosion control and for rebuilding depleted soils. A member of the Leguminosae, so it adds nitrogen to the soil through the actions of root bacteria.