Black walnuts are used in ice cream, candy and commercial baking. The shells of the black walnut may be ground finely and used as an abrasive polish or added to well-drilling mud. A source of excellent lumber, the black walnut is one of the most popular trees for furniture-making.
Depending on the latitude at which the black walnut tree is located, the hard, round, green husks fall off the tree around September or October. To test for good nuts, place dehulled nutshells in a bucket of water; the ones that float contain bad nut meat.
Chemicals found in the leaves, roots, nut husks and trunk of the black walnut can impede the growth of fruits and vegetables growing nearby, such as tomatoes, blackberries, potatoes, grapes and alfalfa. The effects of this chemical remain, even after the tree is removed.
The black walnut tree provides fodder for wildlife who consume the rich nut meats. These animals include squirrels, woodpeckers and white-tailed deer.
Black walnut lumber is valued for its properties as veneer for doors, cabinetry, wall paneling and tables. Gunstock blanks and novelty items are fashioned from black walnut. Wooden figurines are made from the burls, crotches and stumps of the black walnut tree.