Facts About the Black Walnut Tree

Facts About the Black Walnut Tree image by K. A. Arbuckle
Facts About the Black Walnut Tree image by K. A. Arbuckle


The Juglans nigra, commonly known as the Black Walnut tree, is native to the eastern half of the United States. Though grown primarily as a shade tree, its other uses make it one of the most valuable native trees.

The bark of a Black Walnut tree.


A large tree with a rounded crown, the Black Walnut has deeply grooved and brownish-black bark. Between nine and 23 serrated leaflets make up each leaf. Dark green leaves turn yellow in the fall.


The tree often spreads through squirrels burying the nuts. Black Walnut requires sunny locations with rich, moist but well-drained soil.


The tree reaches heights of 70 to 90 feet with a 70-foot spread. The trunk diameter grows up to 4 feet.


Small, light green flowers appear in early spring. An individual tree produces both male and female flowers.


Prized for its hardwood, the black walnut is used for furniture, gunstock and veneers. The tree provides nutritious edible nuts with husks that have value as a dye.

A squirrel's discarded shell and fallen leaves.


Black Walnut produces a known toxin, juglone, which affects sensitive plants, such as tomato, asparagus, apple, lilac, rhododendron and blueberry. Locate gardens away from the tree and don't use any parts for mulch.


  • National Audubon Society Field Guide to North American Trees, Eastern Region; Elbert L. Little; 1980
  • Ohio Department of Natural Resources
  • Purdue University
Keywords: black walnut tree, native trees, edible nuts

About this Author

Kit Arbuckle is a freelance writer specializing in topics such as health, alternative medicine, beauty, senior care, pets and landscaping. She has training in landscaping and a certification in medicinal herbs from a botanical sanctuary.

Photo by: K. A. Arbuckle