Juglans cinerea Seeds | Butternut

Oblong, pointed butternut nuts in sticky green husks on a leafy branch — Butternut (*Juglans cinerea*): Juglandaceae, moist woodlands of eastern North America.

LATIN NAME: Juglans cinerea

COMMON NAME: Butternut

Plant Profile

Butternut is the walnut of the eastern woodland, and its nuts are the richest and sweetest of the American species: oblong, sharply pointed and set in a sticky, downy husk that stains everything it touches. The tree grows to twenty metres with a wide, open crown and long, drooping leaflets, and its bark carries broad, flat ridges that are unmistakable once seen. It is a tree of deep, moist, rich soil and cold winters, and it has been in retreat for a century. The wood is soft and pale, and the whole tree has a slightly untidy, generous look. Butternut is easily confused with black walnut, but its nuts are longer, its bark smoother and its pith chocolate-brown rather than pale.

Science & Biotechnology

Butternut canker, caused by the fungus Ophiognomonia clavigignenti-juglandacearum, has killed most of the species across its range since the 1960s, entering through wounds and buds and girdling stems within a few seasons. The US Forest Service treats it as a species of conservation concern. Some trees show partial resistance, and breeding programmes cross them with Japanese walnut, J. ailantifolia, producing fast-growing hybrids sold as buartnut. Those hybrids backcross readily, which risks swamping the remaining pure stock, so conservation plantings now use seed from tested survivors rather than nursery hybrids. Seed from resistant trees is now collected and grown in orchards, and the canker is the reason butternut is one of the few walnuts with a formal conservation plan.

Uses & Benefits

The nuts are excellent, sweet and oily, and they were once a household crop in New England and the Appalachians, gathered, hulled and pressed for oil. The wood is light, soft, easily worked and takes a fine finish, and it was used for furniture, panelling, cooperage and small carved goods. The inner bark was a traditional astringent, and the sap was boiled for sugar in early spring. In the garden it is a fast, handsome shade tree for moist ground, and in conservation plantings it is grown for its resistance to the canker. The nuts keep poorly because of their high oil content, so they are best used within a season, and they were traditionally gathered in October and hulled straight away.

Growing from Seed

Sow fresh nuts in autumn where they are to grow, or stratify for three to four months and sow in spring, five centimetres deep. Remove the husk but leave the shell intact, and wear gloves, because the husk stains and irritates the skin. Germination is usually good and the seedling grows fast, up to half a metre in its first year. Give it deep, moist, well-drained soil, full sun and space, and protect the young trunk from strimmers, voles and deer, which all find the bark palatable. It also transplants badly because of the taproot, so choose the site before you sow. Seed collected from a tree that has survived the canker is worth more than any nursery label.

Our Take

A fine nut and a fine timber tree, now a conservation subject as much as a garden one, and best planted with that in mind. Buy stock from tested seed where you can.

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