Chestnut trees are a dual-purpose tree, producing both timber and nuts. Chestnut trees are one of the most valuable timber trees grown in the United States. Because of chestnut blight, most of the chestnut trees grown commercially in the United States are either European, Chinese or an American chestnut hybrid. Chestnut trees grow in zones 4 though 8 but do best in zones with hot summers. Chestnut trees are drought-tolerant, but for consistent nut production they must be irrigated. Chestnut trees are excellent shade trees, they provide dappled shade and they will grow in areas other trees will not.
Select chestnut tree cultivars hardy to your region. Chestnuts are not self-fertile and need a pollinator for nut production. For more efficient pollination and larger nut crops, choose two different cultivars for cross-pollination.
Choose a site with fast-draining, sandy to sandy-loam soil in full sun with a pH of 5.5 to 6.5. You can plant chestnut trees in clay soil as long as the site is on a slope for fast drainage of surface water.
Dig a hole just large enough for the roots or root ball. Make sure the roots are fully covered. If you are planting a grafted chestnut, make sure the graft is 2 to 3 inches above the soil. Tamp the soil around the roots and water well. For commercial nut growers, plant trees 40 feet apart. If you want to harvest timber as well as nuts, space trees 25 feet apart, and as trees mature, harvest every other tree for a final distance of 35 feet for nut-producing trees.
Protect young trees from deer. Either use electric or other fencing to keep deer out of the area or surround the young tree with a tree cage. Tree cages are made of wire and enclose the entire tree (sides and top). For older trees, a plastic tree guard wrapped around the trunk can be used. Remove the tree guard from the trunk in the fall and readjust to accommodate trunk growth.
Prune chestnut trees only when necessary. They need very little pruning. You may have to prune crossing and inward pointing branches. The final result should be a tree with evenly spaced branches pointing away from the trunk and approximately the same number of branches on each side.
Fertilize each tree in the spring with either a 5-10-5 or a 10-10-10 fertilizer. Apply 1 lb. of fertilizer for each year the tree is alive. Sprinkle the fertilizer at the drip zone of the tree.
Maintain a 3-foot weed-free zone around the trunk. To keep weeds in check, apply mulch to a depth of 2 inches. Keep the mulch 1 to 2 inches away from the trunk; the mulch should look like a doughnut with the trunk rising from the "hole."
Irrigate chestnut trees planted for nut production during the growing season for heavier nut production.
Treat chestnut trees for fungal and insect diseases. The most devastating are chestnut blight, ink disease, chestnut gall wasp and chestnut weevils. Select cultivars that are resistant to ink and chestnut blight resistant. Spray pesticides for gall wasps and chestnut weevils. For an organic approach, chickens and guinea fowl kept in chestnut orchards will eat insect pests.
Expect nut production to start when the tree is 2 to 10 years old, depending on the cultivar. The older the tree, the more nuts are produced. Nut production can vary from 14 lb. to over 100 lb. of nuts per tree. To harvest chestnuts, the trees are allowed to drop the nuts, and they are gathered from the ground. Large orchards use nets suspended from the bottom branches to catch the nuts.