Black Walnut
Juglans nigra · Deciduous broadleaf hardwood
Plant Family
Juglandaceae
Tree Category
Nut tree and shade tree
Variety / Cultivar
Species type (wild type), no specific named cultivar identified
Hardiness Zones
Thrives in USDA Hardiness Zones 4 through 9, demonstrating broad adaptability to varying continental temperate climates
About This Tree
A large, stately deciduous tree with a rounded, open crown, strong central trunk, and spreading branches. Noted for its heavy production of green, spherical husk-covered nuts clearly visible hanging from the branches.
Leaf Characteristics
Alternate, pinnately compound leaves, typically 12 to 24 inches long, featuring 10 to 24 leaflets plus a terminal leaflet. Leaflets are ovate-lanceolate with finely serrated margins and a smooth green texture turning yellowish in autumn
Bark Characteristics
Dark brown to nearly black bark, deeply furrowed into narrow, rounded ridges creating a distinct diamond-shaped pattern that becomes rougher and thicker with age
Growing Information
Origin Region
Native to central and eastern North America, well-adapted to rich, deep soils in temperate regions worldwide
Growing Season
Leafs out in late spring, flowers in mid-spring, produces fruit through summer that ripens and drops in autumn, enters winter dormancy after frost
Sunlight & Water Needs
Requires full sun for optimal growth and fruit production. Prefers moist, deep, well-draining soils but has 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
Produces valuable dark hardwood timber and edible nuts. Contains juglone, a chemical compound that inhibits the growth of certain companion plants (allelopathy)
Wildlife & Ecology
Supports numerous mammals such as squirrels and chipmunks that consume the nuts, provides nesting sites for various bird species, and serves as a host plant for several moth larvae