Black Walnut
Juglans nigra · Deciduous Broadleaf Hardwood
Plant Family
Juglandaceae
Tree Category
Nut and Shade Tree
Variety / Cultivar
Species type (Native)
Hardiness Zones
USDA Hardiness Zones 4 through 9.
About This Tree
A large, stately tree with a high, rounded canopy. Known for its dark, deeply furrowed bark and compound leaves. It has an open crown density and a moderate growth rate, reaching significant heights at maturity.
Leaf Characteristics
Pinnately compound, 12-24 inches long with 15-23 leaflets. Leaflets are ovate-lanceolate, finely serrated, and bright green, turning yellow in autumn. Arranged alternately on branches.
Bark Characteristics
Dark grey-brown to black, thick and deeply furrowed into diamond-shaped ridges. The inner bark reveals a chocolate-brown color when scraped.
Growing Information
Origin Region
Native to North America (Eastern United States and Southern Ontario)
Growing Season
Leafs out late spring (April/May), flowers in late spring with catkins, fruits mature in fall (September/October), enters dormancy early autumn.
Sunlight & Water Needs
Full Sun required for optimal growth. Prefers moist, well-drained, fertile loamy soils. Moderate drought tolerance once established.
Mature Size
Mature height of 70-100 feet with a spread of 60-80 feet. Growth rate is moderate. Can live up to 250 years.
Special Characteristics
Produces edible nuts with high oil content. Highly prized for dark, fine-grained timber. Produces juglone, a chemical that inhibits the growth of certain other plants (allelopathy).
Wildlife & Ecology
Nuts provide a critical high-fat food source for squirrels, woodpeckers, and foxes. Host plant for the Luna Moth caterpillar. Provides excellent nesting structure for large birds.