188 Juglans nigraCommon Names: black walnut, eastern black walnut, American walnut Family: Juglandaceae (walnut Family)
Black walnut is a large deciduous tree reaching heights of 70-100 ft (21-30 m) or more. This is a vigorous, spreading tree which can develop a trunk 2-4 ft (0.6-1.2 m) in diameter, and a crown spread of 70 ft (21 m). In forest stands, black walnut usually has a long, clear bole and a small, open crown. When grown out in the open, however, it has a short trunk and a massive spreading crown. Black walnut has large, aromatic, compound leaves, 1-2 ft (30-60 cm) long. It bears rather large oval corrugated nuts that are encased in a thick, fleshy yellow-green hull.
Juglans nigra is native to North America, from Massachusetts and southern Ontario to Nebraska, south to Texas, and east to Georgia. It grows best on deep, moist and fertile soils, such as occur along river bottoms.
CultureLight: Black walnut is intolerant of shade. Plant in full sun. Moisture: It likes a moist, well drained soil. Hardiness: USDA Zones 4 - 9. Propagation: Seeds should be planted in a seed bed as soon as ripe. Named cultivars are grafted onto seedlings.
Black walnut has many uses in the forest products trade, and is often recognized as one of the most valuable of North American hardwoods. It is commonly used for gun stocks, cabinetry, and the creation of both solid and veneered furniture. Unfortunately, its extreme value has contributed to its extirpation in many parts of its range where it was formerly common. The nuts are oily, sweet and quite edible, used most commonly for baking and confections. This large, spreading tree makes an excellent shade and specimen tree throughout its range.
For sheer elegance, a mature, open grown black walnut tree's massive form and long green leaves cannot be surpassed. Its oily nuts possess a distinctive flavor that makes its English relative pale by comparison.
The black walnut tree creates a zone around its roots that is antagonistic to many other plants. It is thought that this is caused by a chemical, juglone, produced by the tree's roots. Actual contact with the roots by other plants is needed for this reaction to occur. It is not harmful to people or other animals. Although the virtues of its large foliage and edible nuts have been previously extolled, these same leaves and nuts can be a nuisance to clean up in the fall, especially if you do not plan on eating the nuts!
Steve Christman 12/09/97; updated 09/17/06