Juglans ailanthifolia
Japanese Walnut
a perennial woody deciduous member of the Juglans genus in the family Juglandaceae.
Taxonomy and growth
- Family
- Juglandaceae
- Genus
- Juglans
- Life cycle
- perennial
- Foliage
- deciduous
- Woodiness
- woody
- Height
- 20 m
- Spread
- 15 m
- Fertility
- Self fertile, Wind
- Flower type
- monoecious
- Pollinators
- Wind
Uses
Edible uses
This section contains historical Plants For A Future notes marked noncommercial.
Seed - raw, cooked or used in confectionery[14][2][7][10]. A very good flavour[11]. The shell is easily cracked[4]. An edible oil is obtained from the seed, but it tends to go rancid quickly[10]. Young buds (flower?) and fruit stalks - cooked[2][7][10].
- Plant part
- Leaves
- Product or use
- Oil
- Plant part
- Seed
Medicinal uses
Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
The bark is anthelmintic, astringent, diuretic, lithontripic, pectoral, skin, tonic (kidneys)[8].
- Product or use
- Anthelmintic
- Product or use
- Astringent
- Product or use
- Diuretic
- Product or use
- Kidney
- Product or use
- Lithontripic
- Product or use
- Pectoral
- Product or use
- Skin
- Product or use
- Tonic
Material uses
This section contains historical Plants For A Future notes marked noncommercial.
A brown dye is obtained from the seed husks and the bark[16]. Rich in tannin, it does not require a mordant. The bark is rich in tannin. It is used as a dye and also medicinally[8]. 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[9][12][5]. 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.)[13]. Wood - soft, light, not easily cracked, of good quality. Used for cabinet making etc[15][16].
- Product or use
- Dye
- Product or use
- Herbicide
- Product or use
- Tannin
- Product or use
- Wood
Ecology and functions
- Ecosystem niche
- Canopy
Environment
- Range
- E. Asia - Japan.
- Habitat
- Forests[3].
- Light
- full sun
- Shade tolerance
- no shade
- Water
- moderate
- Hardiness
- Zone 4+
- Soil textures
- sandy, loamy, clay
- Soil pH
- acid, neutral, alkaline
- Drainage
- well drained
- Tolerates Nutritionally Poor Soil
- No
- Drought
- intolerant
Propagation
This section contains historical Plants For A Future notes marked noncommercial.
The seed is best sown as soon as it is ripe in individual deep pots in a cold frame[19]. 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[18][19].
Cultivation
This section contains historical Plants For A Future notes marked noncommercial.
Requires a deep well-drained loam and a sunny position sheltered from strong winds[1][3]. Prefers a slightly alkaline soil[13]. This is the hardiest member of the genus, capable of growing in all areas of Britain[17]. It is also resistant to the attacks of most insects[6]. The young growth in spring, however, can be damaged by late frosts. This species is cultivated for its edible seed in Japan, it has the potential for producing very superior nuts, especially if hybridized with J. cinerea[4][6]. Trees can come into bearing within 3 - 4 years from seed[17]. Plants produce a deep taproot and they are intolerant of root disturbance[1][3]. Seedlings should be planted out into their permanent positions as soon as possible and given some protection since they are somewhat tender when young[1][3]. Flower initiation depends upon suitable conditions in the previous summer[13]. 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[13]. 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[13]. Trees have a dense canopy which tends to reduce plant growth below them. We have no specific information for this species, but the roots of several 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.)[13]. The leaves of many species also secrete substances that have an inhibitory affect on plants growing underneath them. All in all this is not a very good companion plant[K].
References
F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00
Tanaka. T. Tanaka's Cyclopaedia of Edible Plants of the World. Keigaku Publishing 1976-00-00
Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00
Rosengarten. jnr. F. The Book of Edible Nuts. Walker & Co. 1984-00-00 ISBN 0802707699
McPherson. A. and S. Wild Food Plants of Indiana. Indiana University Press 1977-00-00 ISBN 0-253-28925-4
Natural Food Institute, Wonder Crops. 1987.
Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169
Stuart. Rev. G. A. Chinese Materia Medica. Taipei. Southern Materials Centre
Philbrick H. and Gregg R. B. Companion Plants. Watkins 1979-00-00
Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9
Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications 1972-00-00 ISBN 0-486-20459-6
Riotte. L. Companion Planting for Successful Gardening. Garden Way, Vermont, USA. 1978-00-00 ISBN 0-88266-064-0
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Sholto-Douglas. J. Alternative Foods.
Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959-00-00
Usher. G. A Dictionary of Plants Used by Man. Constable 1974-00-00 ISBN 0094579202
Howes. F. N. Nuts. Faber 1948-00-00
Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00
McMillan-Browse. P. Hardy Woody Plants from Seed. Grower Books 1985-00-00 ISBN 0-901361-21-6