Black Walnut
Juglans nigra · Deciduous, Broadleaf, Hardwood
Plant Family
Juglandaceae
Tree Category
Shade Tree, Nut Tree, Forest Tree, Timber Tree
Variety / Cultivar
None specified (wild species)
Hardiness Zones
USDA Zones 4-9; highly adaptable to various temperate climates.
About This Tree
A large, fast-growing hardwood with a massive, rounded, and somewhat open crown. It is characterized by its tall, straight trunk and sturdy, ascending branches that provide light, dappled shade.
Leaf Characteristics
Pinnately compound, 12-24 inches long, with 15-23 ovate-lanceolate leaflets. Fine-toothed margins; yellow-green color turning clear yellow in autumn. Arranged alternately.
Bark Characteristics
Greyish-brown to black, deeply furrowed into a diamond-shaped pattern with rough, interlacing ridges. Inner bark is dark brown when cut.
Growing Information
Origin Region
Native to Eastern and Central North America; naturalized in many temperate regions.
Growing Season
Leafs out late in spring and is one of the first trees to drop leaves in autumn. Flowers (catkins) appear in late spring; nuts ripen in fall.
Sunlight & Water Needs
Full sun is required; it is shade-intolerant. Prefers deep, moist, well-drained loamy soil. Moderate drought tolerance once established.
Mature Size
70-100 feet tall and wide at maturity. Fast growth rate in youth, slowing with age. Can live up to 250 years.
Special Characteristics
Produces 'juglone', an allelopathic chemical that can inhibit the growth of certain nearby plants. Highly valued for its dark, fine-grained heartwood used in furniture and cabinetry.
Wildlife & Ecology
Nuts provide a vital food source for squirrels and other rodents. Host plant for various moth larvae, including the Luna Moth. Provides high nesting sites for raptors.