Black Walnut

Black Walnut, Juglans nigra

Black Walnut is a native tree that can be found throughout the eastern and central portions of the United States. It will average 30 m (100 ft) tall and matures in 150 years, but may produce a small batch of nuts by 4 to 6 years and start producing a larger batch at 20 years. They thrive best in deep, well drained neutral soil with direct sunlight. The hard nut produced contains a sweet, oily meat enjoyed by wildlife and humans. The heavy, very resistant wood itself is highly prized for furniture and has been traditionally used for gun stocks, fencing, and airplane propellers.

Bark of a black walnut tree.

Many native groups have used parts of black walnut for everything from teas, to dyes, to treating ringworm; however, it should be noted that the bark is poisonous. One specific toxin produced by black walnut is known as juglone. This toxin inhibits the growth of other plants up to 25 m (80 ft) around it by depriving sensitive plants of energy needed for photosynthesis. As black walnut is a generally intolerant tree, juglone helps to reduce possible competition. Species that do survive juglone do not necessarily thrive.