Black Walnut
Juglans nigra · Deciduous, Broadleaf, Hardwood, Native
Plant Family
Juglandaceae
Tree Category
Nut Tree, Shade Tree, Timber Tree
Variety / Cultivar
None specified; wild-type species
Hardiness Zones
USDA Hardiness Zones 4-9
About This Tree
A large, fast-growing deciduous tree with a straight trunk and a broadly rounded, open crown. Notable for its high-value dark wood and edible nuts encased in thick green husks.
Leaf Characteristics
Pinnately compound, 12-24 inches long, with 15-23 ovate-lanceolate leaflets. Leaflets are finely serrated and medium green, turning yellow in fall. Arrangement is alternate.
Bark Characteristics
In young trees it is smooth and greyish-brown; it develops deep, diamond-shaped furrows and thick, dark brown to blackish ridges as it matures.
Growing Information
Origin Region
Native to Eastern North America (from South Dakota to New Jersey and south to Florida and Texas)
Growing Season
Leafs out late in spring; flowers in late spring to early summer (catkins); fruits ripen in autumn; drops leaves early in autumn usually after a yellow color change.
Sunlight & Water Needs
Full sun is required for optimal growth; prefers moist, well-drained, fertile loamy soils but has moderate drought tolerance once established.
Mature Size
Mature height of 70-100 feet with a similar spread of 70-100 feet; fast growth rate; can live 150-250 years.
Special Characteristics
Produces juglone, a chemical that inhibits the growth of many other plants (allelopathy); highly prized for fine furniture and gunstocks; distinctive aromatic smell in crushed leaves.
Wildlife & Ecology
Provides high-protein food for squirrels and other rodents; supports various moth larvae including the Luna Moth; provides nesting sites for birds; juglone affects the surrounding plant community composition.