A comprehensive database of Tennessee native plants
Black Walnut, Eastern Black Walnut
Full sun; moderately wet to moderately dry moisture level; requires deep, fertile loam soil; neutral to slightly alkaline pH.
50-75 feet height by 50-75 feet spread; yellowish green male catkins and female flower spikes in late spring; nuts enclosed in tough, 2 inch, round, black, ridged shells with an outer covering of light green flesh in September to October.
Growth Rate: Fast. On best sites, young trees can grow 36-48 inches per year. Tree grows rapidly when young and then slows down with age to a moderate growth rate.
Maintenance: No serious insect or disease problems
Propagation: Seed germination code C (60-120) at 41 degrees F. Moderately easy from seed. Nuts lose viability if allowed to dry out.
Native Region: Middle and East Tennessee
A large, rugged canopy tree which is best for the large landscape and not a good street tree. Very long-lived, maturing at about 150 years and may live to 250 years. Second most valuable native nut tree of North America, second only to the Pecan. Prefers moist soil but tolerates drought conditions although the tree’s growth will be slowed. Intolerant of shade. Usually takes 20 years before a tree will produce large fruit crops. Nuts are edible but hard to extract. When mature, nuts drop to the ground where the husks turn black as they rot away. Husks can stain clothing and sidewalks. Leaves release a chemical called juglone that retards growth of many other plants growing nearby.
Host to several large, showy moth species including Luna moth and Regal moth, and also to some species of butterflies including the Hickory Hairstreak and Banded Hairstreak. Birds, squirrels and humans eat the nuts.