The American Chestnut: Resurrection of an American Classic
The American Chestnut (Castanea dentata) was once one of the predominant tree species on the Eastern seaboard. It ranged from Maine to Florida and from the Piedmont west to the Ohio valley. An estimated 25% of the trees in the forests of Appalachia were American Chestnuts, some of them reaching heights of 120 feet and diameters of 10 feet or more.
The chestnuts were reliable yearly mast producers and were one of the most important food sources for dozens of different wildlife species, from black bears to passenger pigeons, as well as pigs and other domestic livestock. The nuts were also considered a delicacy by humans, though ironically the line that immortalized the delicious nut – “chestnuts roasting on an open fire” – was written in the 40’s when the chestnuts were already nearly gone.
The American Chestnut was an important timber tree – lightweight, easily worked, and extremely resistant to rot – and the combination of nut collecting and lumber production made up a major part of the rural economy of the region.
Then, in 1904, a few trees at the Bronx Zoo in New York began to die. The culprit was chestnut blight, accidentally introduced into New York on some infected Chinese Chestnuts. The blight spread like wildfire through the eastern woodlands, killing an estimated 4 billion chestnut trees and changing the ecology of the region forever. By 1950, the beautiful American Chestnut was nearly extinct, surviving only in a few scattered individuals and patches where the blight had been less virulent, mostly outside the chestnut’s native range. Sprouts occasionally emerge from the surviving roots of once mighty trees killed by the blight, but these are becoming less frequent as time goes on and they rarely survive longer than 15 years before succumbing to the blight themselves.
A number of groups, including the American Chestnut Foundation, the American Chestnut Cooperators Foundation, the US Forest Service’s American Chestnut Restoration Project, the Canadian Chestnut Council, and others are working to develop blight-resistant strains of the American Chestnut by crossing and backcrossing surviving trees and sprouts with Chinese Chestnuts (which evolved with the blight and are highly resistant to it). Early research into genetic modification to impart blight resistance has also taken place.
Today, the inferior Asian and European species are the primary source of chestnuts in the United States, and they can be a useful addition to a stand of native mast-producing trees. It may also be possible to become a cooperating grower of pure or hybrid American Chestnuts. One of the best and most popular hybrid AmericanxChinese chestnuts is the Dunstan Chestnut, developed by Dr. Robert Dunstan, which is blight resistant and produces large, tasty, and easy-to-peel nuts.
In addition to the ongoing efforts to develop a blight-resistant hybrid chestnut, chestnuts are one of the main species being used in woody agriculture research, thanks to their delicious and nutritious nuts, quality wood, and relatively quick growth.