Black Walnut
Juglans nigra · Deciduous Broadleaf Hardwood
Plant Family
Juglandaceae
Tree Category
Shade Tree, Nut Tree, Timber Tree
Variety / Cultivar
None specified; typical of the wild species species
Hardiness Zones
USDA Zones 4-9
About This Tree
A large, stately forest tree with an open, spreading crown and high branches. Known for its high-quality dark timber and edible walnuts. It often exerts allelopathy through its roots.
Leaf Characteristics
Pinnately compound, 12-24 inches long, with 10-24 leaflets. Leaflets are lanceolate, finely serrated, yellow-green in summer, turning clear yellow in fall.
Bark Characteristics
Deeply furrowed, dark gray-brown to blackish, often forming a diamond-shaped or 'X' pattern of interlacing ridges. Inside bark is chocolate brown.
Growing Information
Origin Region
Native to Eastern North America and well-adapted to Central and Southern United States
Growing Season
Late leafing in spring, early leaf drop in autumn; flowers in late spring/early summer; nuts mature in fall
Sunlight & Water Needs
Full sun; prefers deep, rich, moist, well-drained loamy soils; moderate drought tolerance once established.
Mature Size
70-100 feet tall, 60-100 feet spread, growth rate is moderate, lifespan of 150-250 years.
Special Characteristics
Produces juglone (allelopathic chemical), valuable dark heartwood, high edible nut value, and excellent decay resistance.
Wildlife & Ecology
Provides significant food for squirrels and birds; host plant for several moth species (e.g., Luna Moth). Inhibits growth of some nearby plants.