Black walnuts add a nice flavor and texture to many cooked foods including cookies and breads. They are even delicious when eaten raw. However, the shells contain a substance called juglone, which is toxic for many plants, including tomatoes and rhododendrons. For this reason, black walnuts should not be composted. Instead, dispose of them in a different manner.
Wear gloves or use tongs when handling black walnuts. The liquid from the nuts will stain your hands, which are difficult to remove.
Gather the walnuts from the ground when they drop. They usually will drop for about 6 to 8 weeks beginning in the late summer. Place the nuts in buckets to be transferred later or put them directly into garbage bags.
Bag up the black walnuts, preferably into paper bags, which will decompose along with the nuts.
Throw them out with your regular trash or take them to a local dump that has a yard waste-dumping area.