Black Walnut
Juglans nigra · Deciduous Broadleaf Hardwood
Plant Family
Juglandaceae
Tree Category
Nut / Timber / Shade Tree
Variety / Cultivar
None (Wild-type)
Hardiness Zones
USDA Hardiness Zones 4-9; adaptable to most temperate climates with deep soil.
About This Tree
A large, stately forest tree with a deep, dark brown furrowed bark. It typically features a straight trunk with a high, rounded, and open canopy. Known for its valuable dark heartwood and large edible nuts.
Leaf Characteristics
Pinnately compound, 12 to 24 inches long, with 15-23 ovate-lanceolate leaflets. Leaves are medium green, turning yellow in autumn, and arranged alternately.
Bark Characteristics
Dark gray-brown to nearly black, thick, and deeply furrowed into narrow, rough, diamond-shaped ridges. The inner bark shows chocolate-brown layers when cut.
Growing Information
Origin Region
Eastern North America, adapted to fertile river bottoms and moist hillsides.
Growing Season
Late spring budding, early autumn leaf drop; produces nuts in late summer/fall.
Sunlight & Water Needs
Full Sun; requires moist, well-drained, fertile soil. Moderate drought tolerance once established.
Mature Size
70-100 feet tall with a 60-80 foot spread; growth rate is moderate to fast in early years; lifespan up to 250 years.
Special Characteristics
Highly valued for furniture-grade timber; leaves and roots produce juglone, a chemical that inhibits the growth of certain other plants (allelopathy); attracts squirrels for its nuts.
Wildlife & Ecology
Provides essential food for squirrels and other rodents who cache the nuts; serves as a host plant for the Luna Moth and several species of beetles; offers nesting sites for larger birds.