Black Walnut
Juglans nigra · Deciduous broadleaf hardwood
Plant Family
Juglandaceae
Tree Category
Nut and Shade Tree
Variety / Cultivar
Species type (wild type)
Hardiness Zones
Thrives in USDA Hardiness Zones 4 through 9
About This Tree
Large, stately deciduous tree with a straight trunk, rounded open crown, and compound foliage providing dappled shade; known for producing valuable dark wood and edible nuts encased in a green husk
Leaf Characteristics
Alternate, pinnately compound leaves 1 to 2 feet long, featuring 11 to 23 leaflets that are ovate-lanceolate with finely serrated margins and a terminal leaflet often missing
Bark Characteristics
Dark brown to nearly black bark with deep, narrow ridges forming a distinct diamond-shaped pattern that becomes rougher and more furrowed with age
Growing Information
Origin Region
Eastern and central North America, widely adapted to temperate climates
Growing Season
Spring leaf-out following late frosts, flowering in mid-spring, nut production maturing in autumn, entering winter dormancy late fall
Sunlight & Water Needs
Requires full sun and moist, deep, well-drained soils; moderately drought-tolerant once established but prefers consistent moisture
Mature Size
Reaches 50 to 75 feet in height with a comparable or wider spread, growing at a moderate rate with a lifespan exceeding 130 years
Special Characteristics
Produces juglone, an allelopathic chemical that inhibits the growth of certain surrounding plants; highly prized dark timber, edible nuts, and good tolerance to urban pollution
Wildlife & Ecology
Supports squirrels, rodents, and various birds that consume the nuts; provides nesting sites and cover, though its fallen leaves and roots release juglone which restricts understory plant diversity