Common Name: Kozo

General Information

Broussonetia kazinoki is a deciduous shrub or small tree with an open, spreading habit; it can grow 2 - 4 metres tall[, ].
The plant is harvested from the wild for local use as a food, medicine and source of fibre. It has been cultivated as a fibre plant in Japan.

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - southeastern China, central and southern Japan, Korea.

Habitat

Forest margins, low mountains and near houses[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	3.00 m
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Broussonetia kazinoki is found in southeast China from the warm temperate regions to the tropical island of Hainan. It is moderately frost resistant, though the young growth in spring, even on mature plants, is frost-tender and so it is best to grow the plants in a position sheltered from the early morning sun[].
Easily cultivated in a warm sunny position in any soil of reasonable quality[, ], thriving on poor sandy or gravelly soils[]. Tolerates atmospheric pollution[].
The tree is often cultivated in Japan, where it is coppiced annually to provide bark from which a fibre is obtained for making paper[, ].
Some plants are monoecious whilst others are dioecious. Male and female plants must usually be grown if seed is required[].

Edible Uses

Fruit - raw[, ]. A sweet taste[]. The fruit comprises a ball about 1cm in diameter with small edible fruits protruding - there is not much edible flesh but it has a lovely flavour[]. Prolonged ingestion of the fruit is said to weaken the bones[].

Leaves - cooked and used as a vegetable[, , ].

Flowers[, , ]. No more details.

Medicinal

The fruit is used as a tonic to increase vision and sexual potency[].
The plant (part not specified) is a traditional medicine, used in the treatment of blurred vision, plus inflammatory and infectious diseases[].

Other Uses

A fibre from the bark is used in making paper, cloth, rope etc[, ]. A good quality fibre, especially for making paper, though it is considered to be inferior to the fibre from Broussonetia papyrifera[].

Propagation

Seed - no pre-treatment is required. Sown in the autumn or spring in a greenhouse, germination usually takes place within 1 - 3 months at 15°c[]. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter, planting them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, 8 - 12cm long with a heel, mid summer in a frame. High percentage[, ].
Cuttings of mature wood of the current season's growth, late autumn in a frame[].
Root cuttings in winter[].
Layering in spring[].