Black walnuts are ideal for baking and re-planting for other black walnut trees. In either case, they need to have the husk removed first before anything else. The nuts are round in shape and about two inches in diameter, and can usually be harvested from summer to fall after they ripen on the tree. Keep in mind that you will need a large amount of black walnuts if you are using them for baking. On average, two pounds of unshelled black walnuts provides about a cupful.
Put on gardening gloves or use tongs when handling the unhusked walnuts, as the juice can leave dark stain on your hands. Husk only nuts that are ripe. Press on the skin of the walnut with your thumb; ripe nuts will show an indentation.
Create a husk-softening mixture in the bucket by adding three parts black walnuts to one part water and a handful of gravel. Use a large stick or sturdy spoon to vigorously stir this mixture together for about five to ten minutes.
Take the black walnuts out of the bucket and dry them with an old towel that you don't mind getting dirty. Place each walnut on a flat sturdy surface, one by one. Use a hammer to pound the side of the walnut (make sure to wear protective eyewear or goggles) until the husk cracks open. Peel away the husk with your hands. If the walnut is oily and black, discard, as this means it is infested with bugs.
Add the hulled walnuts to a fresh bucket of water to check for insect infestation or disease. Discard any walnuts that float to the top of the water. Keep the nuts that sink to the bottom of the bucket.
Discard the walnut husks; do not add them to your compost pile as they can have a toxic effect of vegetables and plants.