The Black Walnut is a widespread and common deciduous tree that grows as far west as Minnesota and can be up to 100 feet tall. The tree has long alternate, pinnately compound leaves composed of 10-24 leaflets with large, round fruit covered in a thick green indehiscent husk. The sweet, oily, and edible nut inside matures in late summer to fall.

The allelopathic compound, juglone, is found in all parts of the tree. When this leeches in the soil, it deters many plants from germinating. This gives black walnuts a competitive advantage when establishing a stand but it could also potentially prevent productive vegetable gardens if planted too close by. However, many native trees and shrubs can tolerate juglones, such as eastern red cedar, serviceberry, paw, dogwoods, and many others.

The black walnut is a tree of many uses – it provides shelter and food for small mammals and birds. It is highly sought-after wood for cabinet-making, gunstocks, and veneers. The seed and seed casing are used in candy making, cleaning abrasives, and explosives. Historically, it was often used as structural timbers in houses and barns in Kentucky. Black walnut is also the most common host plant for mistletoe.

Images courtesy of:
Ohio State University
Robert Videki
University of Georgia
Iowa State University