Starting American Chestnut Trees

The American Chestnut Tree, (castanea dentata), is a large, fast-growing deciduous tree, of the beech family, native to eastern North America. As is true of all species in the genus Castanea, the American chestnut produces burred fruit with edible nuts.

The American Chestnut almost disappeared from eastern North America due to an epidemic caused by a fungal disease called the chestnut blight (Cryphonectria parasitica). In Canada, the American Chestnut is restricted primarily to southwestern Ontario. Based on information available in 2004, it was estimated that there are 120 to 150 mature trees and 1,000 or more small, young trees in the province. Not much for a place that is over 1 million square kilometers (415,000 square miles) in size.

I used to grow bonsai trees until one day my goat got into where I wintered my bonsai and he ate them all, so now I just start trees and plant them on my friends and families’ properties. Most of the trees I start like sugar maple, oak, or pine, take two or more years to grow over 1 foot. This American Chestnut is just one and a half months old from a sprouting seed to a seedling, and it is all ready 16 inches tall. I think I’ll plant this one at my buddy George Squirrell’s place.

Chances are you have almost everything you need to start nut trees.

Raw nuts, not cooked or roasted nuts they are dead. I got my nuts from my local groceries store.

A bowl of water to soak the nuts in.

Paper towels, peat moss, or some other moist medium. I used paper towels.

A Ziploc bag or some other watertight container.

Potting soil

Pots, I like to reuse food containers instead of buying new pots.

Most nut seeds need a water soak to check for viability where floaters are usually bad.

Some nuts or pits like cherry or plum, may need a nick in the shell, (scarification), to help germinate.

To germinate sweet chestnut seeds, first soak seeds in water for 24 hours, they don’t need scarification.

After 24 hours discard any floaters, they are usually bad.

Most trees that experience winter need cold stratification, (winter for them to germinate).

Place the chestnuts in a moist medium and refrigerate for 60 to 90 days at about 34° to 41°F or 1° to 5°C to break dormancy.

This process mimics winter, allowing the nuts to germinate and sprout.

If you are going to plant the nuts outside for the winter, bury the nuts about 1 to 2 inches deep in well draining soil. Cover with a wire mesh to keep rodents away and mulch to protect the nut from frost.

The nuts don’t sprout all at the same time, so check the nuts every week.

Uncover the nuts and look for sprouting roots and mold.

Keep the paper towel moist, discard and replace the paper towel if it has mold growing on it.

Wash mold off the nuts with just water if you find any growing on the nuts.

I look for and wait for root sprouts to reach about ½ of an inch.

When the root sprout reaches about ½ of an inch, plant the nut with the root sprout pointing down in a well draining fertile potting mix.

Keep the soil consistently moist and in a warm in a shaded location initially, moving to morning sun once a stem appears.

After a couple weeks you should see a top sprout reaching for the sun.

After the last frost you can directly plant the nuts outside, burying them about 1 to 2 inches deep in well draining soil and cover with a wire mesh to keep rodents away.

This sprout reached 12 inches tall in one month, most of the pine, maple, and oak trees I start take a couple years to reach this height.

American chestnut trees are known for their fast growth, especially as seedlings, with potential height increases of 4 to 7 feet per year under ideal growing conditions, partial shade and good soil. They are generally considered fast to moderate growers, reaching significant heights quickly. Before the blight decimated the American Chestnuts, historical stump sprouts would grow 42 feet in 20 years.

From a nut to a mature, fruit-producing, chestnut tree, expect the first small harvests of chestnuts in about 3 to 5 years, with more significant yields starting around 8 to 10 years old, reaching peak nut production and maturity about 15 to 25 years producing 50 to 100 pounds of nuts annually. They grow surprisingly fast from seed, sometimes reaching heights like 34 feet in 14 years if growing in a blight free area.

American Chestnut trees are generally hardy in USDA hardiness zones 4 through 8, though some varieties or specific sites might extend this to Zone 9, thriving best in well-drained, acidic soils and requiring full sun to partial shade. They prefer sandy or loamy soils and can struggle with heavy clay, but need good drainage to prevent root issues, often found naturally in the eastern US and Canada's Carolinian Zone.