Black Walnut
Juglans nigra · Deciduous Broadleaf Hardwood
Plant Family
Juglandaceae
Tree Category
Nut and Timber Tree
Variety / Cultivar
Native species (Common Black Walnut)
Hardiness Zones
4-9
About This Tree
Large, majestic tree with an open, spreading crown at maturity. Known for its high-value dark wood and edible nuts. It grows straight with a strong central leader and develops a deep taproot.
Leaf Characteristics
Pinnately compound, 12-24 inches long, with 15-23 ovate-lanceolate leaflets. Margins are finely serrated; color is yellow-green in summer, turning clear yellow in fall.
Bark Characteristics
Deeply furrowed, dark gray-black bark with a characteristic diamond-shaped pattern of ridges and deep fissures. Inner bark is chocolate brown.
Growing Information
Origin Region
Central and Eastern North America
Growing Season
Late leaf-out in spring (May); flowers May-June; fruits ripen in Sept-Oct; early leaf drop in autumn.
Sunlight & Water Needs
Full sun (intolerant of shade); prefers deep, rich, moist, well-drained loamy soils; moderate drought tolerance once established.
Mature Size
70-100 feet height, 60-80 feet spread; growth rate is moderate; lifespan often exceeds 150 years.
Special Characteristics
Produces juglone (an allelopathic chemical that inhibits growth of some nearby plants). Highly valued for furniture-grade timber and edible oily nuts. Very distinct dark wood heartwood.
Wildlife & Ecology
Nuts are a primary food source for squirrels and other rodents. Host plant for the Luna Moth. Provides significant nesting canopy for large birds.