Black Walnut
Juglans nigra • Juglandaceae
🌱 Seed Category
Tree
🌍 Origin Region
Central and Eastern North America; native from Ontario to Florida and west to the Dakotas.
📅 Days to Maturity
12-15 years to produce first significant nut crop; 30-50 years for timber harvest. Nuts ripen in Autumn (September-October).
🌡️ Hardiness Zones
USDA Zones 4-9. Extreme cold hardy perennial tree.
About This Seed
The seed is a globose nut, 3-5cm, featuring a thick, hard, deeply furrowed blackish-brown shell. The resulting plant is a large deciduous tree reaching 70-100 feet with a broad open crown, pinnately compound leaves, and fissured dark grey bark.
Growing Information
Growing Season
Plant in Fall (direct sow) or late Winter (after stratification). High frost tolerance; benefits from winter chill.
Germination
Requires 90-120 days of cold-moist stratification at 33-40°F. Germination takes 4-5 weeks in Spring once soil warms; light is not required for germination but deep soil is.
Planting Instructions
Plant 2-3 inches deep. Spacing should be at least 30-40 feet for mature trees. Prefers deep, rich, moist, well-draining alluvial soils with a pH of 6.0 to 7.0.
Sunlight & Water Needs
Full Sun (6+ hours per day). High water needs during establishment; moderate drought tolerance once mature. Needs consistent moisture for nut production.
Companion Plants
Beneficial: Black Raspberry, Currants, Elderberry, and certain grasses. Avoid: Apple trees, tomatoes, potatoes, peonies, and azaleas (highly sensitive to juglone).
Special Characteristics
Strongly allelopathic (produces juglone), high timber value, edible nut meat, provides wildlife habitat, and resistant to many pests but susceptible to Thousand Cankers Disease.