The season for planting chestnut trees—whether from seeds or seedlings—is springtime. If you are planning to plant this spring, it’s time to be thinking about what you need to do to improve your chances of growing healthy American chestnut trees.
First, consider your planting site. The soil you choose should be well-drained and acidic. A ridge or hillside makes a good site; avoid a bottom or swale. Dry, sandy or gravelly soil is best, but avoid clay or soils that hold water. Choose a spot where the trees will get a minimum of 6-8 hours of sun; chestnut trees will only flower when exposed to full sun. Plant trees at least 8-10 feet apart; more is better to allow for growth. Plant at least two trees if you want nuts; chestnuts are not self-pollinating. To allow for variable survival rates, planting five or more trees at any site is recommended.
Should you plant seeds or seedlings? Planting seeds directly in the soil allows the tree to grow in the environment it will live in for years to come and reduces the time it needs to get established. But starting seedlings in pots lets them get started a little earlier in the growing season and is a good option where rodent predation is a concern.
In either case, plant the seeds on their sides, with the root, or radicle, pointing down. Seeds should be planted 1/2-1 inch deep. In pots, choose a tall (12 inch) narrow pot such as a 2-quart milk carton with large holes punched in the bottom. Use a soilless potting mix.
When should you plant? Seedlings can be started in the late winter if they are to be grown indoors. If they develop leaves, they need to be acclimated for two weeks prior to setting them out by placing them in a protected, shady location. Otherwise, bare root seedlings can be planted as soon as the soil can be worked. It’s best to wait until the threat of hard frost has passed. The same is true for nuts.
Until they are planted, seeds should be stored at 33-40 degrees; a vegetable crisper is ideal. Seal the seeds in plastic bags with a bit of slightly moist peat moss, which has antibacterial properties. The seeds may sprout during storage; this is normal.
After planting, your chestnut trees will need care for the first several years. The plants should be watered at least once a week for the first month and regularly during the first year, especially during dry spells. Be careful not to overwater, though.
The trees will also need protection from a variety of predators, ranging from voles and squirrels to deer and even bears. An effective practice is to make a 3-inch diameter tube of 10-inch aluminum flashing and press it 2-3 inches into the soil around the seed or seedling. This will help with smaller predators. For deer, erect a fence in a three-foot diameter circle around the tree site. The sturdier and higher it is, the better, as deer can be aggressive in going after the tasty plants. The cage will need to stay in place for at least five years.
Weeds too are a significant challenge to young chestnuts. Plan on cultivating around the base of the new trees for the first five years.
The American Chestnut Foundation has many resources to help with planting and maintaining American chestnut orchards and offers help in identifying problems with disease and insect predation. For more information, go to https://tacf.org/resources.
