Black Walnut
Juglans nigra · Deciduous Broadleaf Hardwood
Plant Family
Juglandaceae
Tree Category
Shade Tree / Nut Tree / Forest Tree
Variety / Cultivar
Species native (various regional wild cultivars exist)
Hardiness Zones
USDA Hardiness Zones 4 through 9
About This Tree
A large, majestic forest tree with an open, rounded crown and many ascending branches. Known for its strong, durable wood and edible nuts. It develops a deep taproot and produces juglone, a chemical that can inhibit the growth of certain nearby plants.
Leaf Characteristics
Pinnately compound leaves, 12-24 inches long, with 15-23 ovate-lanceolate leaflets. Leaflets have serrated margins and an alternate arrangement. High yellow-green color in summer, turning clear yellow in autumn.
Bark Characteristics
Deeply furrowed, dark brown to grayish-black bark forming a distinctive diamond-shaped pattern of ridges as it matures.
Growing Information
Origin Region
Native to Eastern North America and Central United States
Growing Season
Late to leaf out in spring; early to drop leaves in autumn. Flowering occurs in May to June; nuts ripen in September to October.
Sunlight & Water Needs
Full Sun is essential; prefers moist, well-drained, fertile soil. Moderate drought tolerance once established, but sensitive to very dry soils.
Mature Size
Mature height of 70-100 feet; spread of 60-80 feet. Moderate growth rate with a lifespan of 150-250 years.
Special Characteristics
Highly prized for dark-colored furniture-grade timber; produces edible nuts; exceptional fall yellow color; notable allelopathic properties (juglone production).
Wildlife & Ecology
Provides critical food for squirrels and other rodents who cache and eat the nuts. Specific hosts for the Luna moth and walnut sphinx moth. Offers nesting sites for large birds due to its sturdy structure.