The greatest concentration of juglone in the soil exists within the dripline of the trees. Vegetable gardens in this area will undoubtedly experience problems. Volunteer walnut seedlings which appear in or near the garden should be removed. Walnut leaves and other plant debris, which may accumulate in the garden, should be raked and removed. Sawdust or wood chips derived from walnuts should not be applied as a mulch around susceptible plants.
Black walnuts can create problems for home gardeners.
Careful selection of juglone tolerant vegetables and shade tolerant annuals and perennials should help overcome these problems. Iowa State University , Ames, Iowa. This information subject to a usage policy .