Common Name: Butternut

General Information

Juglans cinerea is a deciduous tree, usually forming a wide-spreading head of branches over a straight trunk. It usually grows up to 20 metres tall, occasionally reaching 30 metres[].
The plant is harvested from the wild for local use as a food, medicine and source of materials.
Juglans cinerea has a wide range, but is nowheret abundant and the population is also in rapid decline. This is caused by the invasion of the non-native, fungal pest Ophiognomonia clavigignenti-juglandacearum which upon infection can kill trees. The infection can spread quickly and already the pest is found across the species range. There is limited natural resistance to this fungus which was introduced in 1967. Since this time reports of decline from different states varies from 27% to 91%. Due to this variation it is predicted that historical population decline has been up to 80%. This figure is also given to decline across a three generation shifting window and to a suspected decline, over the next 100 years. Efforts are being made to better understand ways to protect butternut from the pest. The plant is classified as 'Endangered' in the IUCN Red List of Threatened Species(2018)[].

Known Hazards

None known

Botanical References

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Range

Central and Eastern N. America - Manitoba to New Brunswick and Nova Scotia, south to Mississippi and Georgia

Habitat

Usually found in rich moist soils of bottomlands and floodplains and along ravines, terraces, creeks and streams in mesophytic forest[, ], but also found on dry rocky soils, especially if these are on limestone[].

Properties

Conservation Status	Endangered
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Growth Rate	Medium
Pollinators	Wind
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Juglans cinerea is the most cold-resistant of the walnuts[], tolerating temperatures down to about -35°c in N. America when fully dormant[]. The tree prefers hot summers, however, and does not grow so well in more maritime climates where the wood may not ripen fully and the young growth in spring can be stimulated into early growth and then be damaged by late frosts[].
Requires a deep well-drained loam and a position sheltered from strong winds[, ]. Prefers a slightly alkaline soil[]. Prefers a sandy soil with a pH around 6 to 7[]. Dislikes compacted soils or clay sub-soils, otherwise trees grow well on most soils[].
Sometimes cultivated in N. America for its edible seed, there are some named varieties[, , ].
Trees can come into bearing in 6 - 10 years from seed and fruiting is usually biennial[]. Seedlings can take feom 20 - 60 years before producing seed[].
The trees are quite short-lived, seldom exceeding 80 - 90 years[]. They require about 105 frost-free days in order to ripen a crop in N. America[]. Unfortunately, they have not proved successful as a nut tree in Britain, usually failing to produce a crop[]. This is probably due to our cooler summers[]. It is sometimes planted as a timber tree in Denmark and Rumania[].
Plants produce a deep taproot and 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 few winters since they are somewhat tender when young[, ].
Trees cast a dense shade which reduces the amount of species able to grow 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.)[]. 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[].
Plants should only be pruned when they are fully dormant in winter or when they are in full leaf, otherwise any cuts will bleed profusely[].
Hybridizes with J. ailantifolia, there are some named varieties of this hybrid that are grown for their edible seed[].

Edible Uses

Seed - eaten raw or ground into a powder and used with cereal flours in making cakes, biscuits, muffins, bread etc[]. Oily and sweet tasting with a rich agreeable flavour[, , 63. 101, ]. The oil in the seed is not very stable and the seed soon becomes rancid once it is opened[]. The kernel is usually only about 20% by weight of the whole seed[] and is hard to extract[]. The unripe fruit can be pickled[]. The seed is 3 - 6cm in diameter and is produced in clusters of 3 - 5 fruits[, ].

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

The sweet sap is tapped in spring and can be used as a refreshing drink[]. It can also be boiled down to a syrup or sugar, or added to maple syrup[, , , , ].

Medicinal

Butternut was used by various native North American Indian tribes as a laxative and tonic remedy to treat a variety of conditions including rheumatic and arthritic joints, headaches, dysentery, constipation and wounds[]. In modern herbalism it is considered to be a valuable remedy for chronic constipation, gently encouraging regular bowel movements. It is especially beneficial when combined with a carminative herb such as Angelica archangelica[]. Butternut also lowers cholesterol levels and promotes the clearance of waste products by the liver[].

An infusion of the inner-bark is used as a cholagogue, febrifuge, mild laxative and stomachic[, , , , , , , ]. It is effective in small doses without causing cramps[].
The bark is best collected in the autumn[]. Best collected in late spring according to another report[].

An infusion of the dried outer bark is used in the treatment of toothache and dysentery[].

The oil from the nuts is used in the treatment of tapeworms and fungal infections[, ].

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 this species 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

A yellow to orange dye is obtained from the seed husks[, , ] and from the bark[]. It is dark brown[, ]. It does not require a mordant[]. The seed husks can be dried and stored for later use[].
A light brown dye is obtained from the young twigs, leaves, buds and unripe fruit[, , ]. It does not require a mordant[]. The leaves can also be dried and stored for later use[].
A black dye is obtained from the young roots[].

Wood - coarse-grained, light, soft, not strong, very attractive[, , , ]. It weighs 25lb per cubic foot[]. It is not as valuable a crop as the black walnut (J. nigra), but is used indoors for furniture, doors etc[].
Butternut is a valued lumber and timber species (NatureServe 2018). The wood can be used to make cabinets, furniture and novelties[].

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[, ].