
Juglans nigra
Black Walnut is a large deciduous tree providing light shade and excellent bright yellow fall foliage. Be thoughtful on where you plant black walnut; it produces an allelochemical called juglone that can inhibit the growth of other plant species. Most native plant species are unaffected by juglone since they evolved within the same range as walnuts. However, non native ornamental plants and some vegetable plants may be more negatively affected. Nut production begins when the tree is about 10 years old and has best production when 30 years old.