Common Name: Manchurian Walnut

General Information

Juglans mandschurica is a deciduous tree that usually grows around 15 - 25 metres tall with a straight, upright trunk[, , ]. The plant sometimes branches from the base and becomes shrubby[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. The seeds are sold as a food in local markets[]. The plant is occasionally cultivated for its seeds and is also grown as an ornamental[].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - Russian Far East, northern and eastern China, N. Korea

Habitat

Mixed woods in humus-rich soils in valleys and inundated forests, also by mountain streams[]. Mixed forests on mountain slopes or in valleys at elevations from 500 - 2,800 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	20.00 m
Pollinators	Wind
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Juglans mandschurica is is a very cold-hardy plant, able to tolerate temperatures down to around -25°c when fully dormant. It prefers a continental climate with its hot summers, cold winters and usually a clear movement from one season to another. It is easily excited into growth as the season warms up and, in areas where periods of mild weather can be interspersed with a return to cold conditions, this new growth is very susceptible to damage by temperatures near to or below freezing
Requires a deep well-drained loam and a sunny position sheltered from strong winds[, ]. Prefers a slightly alkaline soil[].
A very hardy and ornamental tree[], it is recommended for cultivation in severe cold climates[].
Plants produce a deep taproot and they are intolerant of root disturbance[, ]. Seedlings should be planted out into their permanent positions as soon as possible and given some protection for their first winter or two since they are somewhat tender when young[, ].
Flower initiation depends upon suitable conditions in the previous summer[]. The flowers and young growths can be destroyed by even short periods down to -2°c, but fortunately plants are usually late coming into leaf[].
Any pruning should only be carried out in late summer to early autumn or when the plant is fully dormant otherwise wounds will bleed profusely and this will severely weaken the tree[].

Edible Uses

Seed - raw or roasted[, ]. Made into confections and sweetmeats[]. The kernels are well filled but difficult to extract because the shell is thick[, , ]. The shape and size of the seed is very variable, ranging from round to elongate and from 27 - 50mm long[].

An edible oil is obtained from the seed[, ], it tends to go rancid quickly.

Medicinal

The cotyledons are said to be a cure for cancer[].

Agroforestry Uses:

Plants produce chemicals which can inhibit the growth of other plants. These chemicals are dissolved out of the leaves when it rains and are washed down to the ground below, reducing the growth of plants under the tree[, , ]. The roots of many members of this genus produce substances that are toxic to many plant species, especially apples (Malus species), members of the Ericaceae, Potentilla spp and the white pines (certain Pinus spp.)[].

Other Uses

Seedlings are sometimes used as rootstocks for commercial walnut varieties in order to confer greater cold resistance[, ].

The seed contains up to 52% oil and, as well as being edible, it has industrial uses[].

The seed shells are a source of tannins[].
The powdered seed shell is used as an ingredient in commercial cosmetic preparations as an abrasive[].

A rope is made from the bark of young trees[].

The inner bark is used to make heel pieces for straw shoes[].

The wood is hard, durable, easily worked, takes a good polish and has a beautiful texture. It is used for veneer, furniture, turnery etc[, , ].

Propagation

The seed is best sown as soon as it is ripe in individual deep pots in a cold frame[]. You need to protect it from mice, birds, squirrels etc. The seed usually germinates in late winter or the spring. Plant out the seedlings into their permanent positions in early summer and give some protection from the cold for their first winter or two.
The seed can also be stored in cool moist conditions (such s the salad compartment of a fridge) over the winter and sown in early spring but it may then require a period of cold stratification before it will germinate[, , ].