Homeowners with black walnut trees often look forward to the nuts they drop in the fall. According to Kansas State University horticulture expert Cynthia Domenghini, understanding the signs of readiness is essential for successfully harvesting and curing black walnuts.

Black walnuts are ready for harvest when the hull can be easily dented with a thumb, or when the nuts begin to fall from the tree. After harvesting, the hull—the hard outer coating—must be removed promptly; otherwise, the stain from the hull can leach into the nut, causing discoloration and an off-flavor.

It’s important to wear gloves when hulling the nuts, as black walnuts contain a persistent dye that can stain concrete, skin, clothing, and other surfaces, making it almost impossible to remove once set.

Several methods can be used for hulling the nuts. They can be run through a corn sheller or pounded through holes in a board, ensuring the holes are large enough for the nut but smaller than the hull. Another technique involves driving over the nuts on a gravel driveway, which breaks the hull without cracking the nut.

After hulling, unshelled nuts should be washed in a tub of water, discarding any that float, as these are likely empty. To dry the nuts, spread them in a cool, dry area, with no more than three layers deep. A garage or tool shed is suitable for this purpose. After about two weeks, the nuts will be ready to enjoy on their own or in favorite fall dishes.