The Eastern Black Walnut, Juglans nigra, is appreciated as a shade tree as well as for its distinctively flavored nutmeats and beautiful wood. The tree occurs naturally from southern Canada to the Carolinas and west to Iowa, Nebraska, and Kansas.
Nuts or Wood?
While any black walnut tree can produce nuts, growing trees specifically for nut production differs dramatically from growing for high quality timber. Trees in the nut orchard have short trunks and wide spreading branches: all of the leaf energy is channeled into producing nuts rather than wood. Improved cultivars which produce nuts with a high percentage of kernel (20-30% as compared with ~6% from wild trees) that crack out into large pieces are grafted to wild or improved stock.
General Production Notes:
The best walnut production sites have deep, well-drained, fertile soils. Plantings are generally made on a 40'X40' spacing, although some growers recommend 60'X60'. There are many cultivars available from commercial nurseries or, for those who can graft, as scionwood from other growers. These improved varieties crack more easily and produce larger pieces of kernel with less picking. It takes less time to bring improved cultivars into production than wild seedlings but plan on a minimum of 10 years from planting to a significant harvest.
Black walnut trees are subject to late summer anthracnose outbreaks which may reduce nutmeat quality. Some insects cause damage, particularly the fall web worm and the walnut caterpillar, although chemical control is seldom required. Young trees left unprotected may be damaged when they are browsed or rubbed by deer.
One or two trees will provide a family with a generous supply of nutmeats: a single vigorous tree may produce 150 pounds of nuts in one season. If you are considering a commercial venture using hand labor to harvest nuts, you should probably limit your orchard to a maximum of 10 acres. An orchard can produce 1-2,000 pounds of hulled nuts per acre (that means you'll be picking up approximately 3-6,000 pounds of nuts WITH hulls!). Averaging 500 pounds per day (a half acre or less when trees are in full production), your fall will be spent gathering nuts. If you decide to plant several different cultivars, plant them together in blocks: the commercial buyers want lots that contain a single variety.