American Walnut
Juglans nigra · Deciduous, Broadleaf, Hardwood
Plant Family
Juglandaceae
Tree Category
Nut Tree, Shade Tree, Timber Tree
Variety / Cultivar
Native species (Wild type)
Hardiness Zones
USDA Zones 4-9; very adaptable to various temperate climates.
About This Tree
A large, stately forest tree with a high, rounded, open crown and straight trunk. Known for its dark, chocolate-colored heartwood and edible nuts.
Leaf Characteristics
Pinnately compound, 12-24 inches long with 15-23 leaflets; leaflets are ovate-lanceolate with finely serrated margins; medium green turning yellow in fall.
Bark Characteristics
Deeply furrowed on mature trees with a distinctive diamond-shaped pattern; dark gray to blackish in color; inner bark turns dark brown when exposed.
Growing Information
Origin Region
Native to Central and Eastern North America
Growing Season
Leafs out in late spring (one of the last); flowers in spring; fruits ripen in autumn; enters dormancy early
Sunlight & Water Needs
Full sun required; prefers deep, moist, well-drained loamy soils; moderate drought tolerance once established.
Mature Size
70-100 feet in height with a 60-80 foot spread; slow to moderate growth rate; can live 150-200 years.
Special Characteristics
Produces juglone (an allelopathic chemical that inhibits nearby plant growth); highly prized for premium furniture timber; rich fall yellow color.
Wildlife & Ecology
Provides high-protein nuts for squirrels, woodpeckers, and foxes; host plant for Luna Moth larvae; provides significant canopy nesting sites.