Black Walnut
Juglans nigra · Deciduous hardwood
Plant Family
Juglandaceae
Tree Category
Nut Tree / Shade Tree
Variety / Cultivar
Species type (wild type)
Hardiness Zones
Thrives in USDA Hardiness Zones 4 through 9.
About This Tree
A large, stately deciduous shade tree characterized by a straight trunk, a deep root system, and an open, rounded crown. Highly prized for its rich, dark brown heartwood clearly visible in the freshly cut cross-section.
Leaf Characteristics
Pinnately compound leaves, typically 1 to 2 feet long with 15 to 23 leaflets, finely serrated margins, yellowish-green in summer turning yellow in fall.
Bark Characteristics
Dark brown to nearly black, deeply furrowed with narrow, rounded ridges forming a distinctive diamond-shaped pattern.
Growing Information
Origin Region
Native to eastern and central North America, well-adapted to rich, deep bottomlands and moist soils throughout the temperate zones.
Growing Season
Leaves out late in spring and drops leaves relatively early in autumn. Flowers appear in spring as catkins, followed by large green nuts maturing and dropping in autumn.
Sunlight & Water Needs
Requires full sun for optimal growth. Prefers deep, rich, moist, and well-drained soils, though it exhibits moderate drought tolerance once established.
Mature Size
Reaches a mature height of 50 to 75 feet with an equal or greater spread, growing at a moderate rate with a lifespan exceeding 130 years.
Special Characteristics
Renowned for producing heavy, durable, dark brown timber of exceptional value and producing juglone, an allelopathic chemical that inhibits the growth of certain nearby plants.
Wildlife & Ecology
Provides crucial food sources (nuts) for squirrels, foxes, and various birds, while offering nesting sites and dense canopy cover in mixed deciduous forests.