American Chestnut

Castanea dentata

Under a spreading chestnut tree

The village smithy stands

The Village Blacksmith, Henry Wadsworth Longfellow. 1807–1882

Wait.  You thought there were no more American Chestnut trees.  Keep reading.

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American Chestnut Leaves and Nuts – photo: Peatcher at German Wikipedia

The American Chestnut is highly susceptible to chestnut blight, caused by an Asian bark fungus  accidentally introduced into North America on imported Asiatic chestnut trees. The disease was first noticed on American Chestnut trees in 1904 in what was then the New York Zoological Park, now known as the Bronx Zoo by chief forester Hermann Merkel.  Merkel estimated that by 1906 blight had infected 98 percent of the chestnut trees in the Bronx alone. [6]

While Chinese Chestnut evolved with the blight and developed a strong resistance, the American Chestnut had little resistance. The airborne bark fungus spread 50 miles a year and in a few decades girdled and killed up to three billion American chestnut trees.  New shoots often sprout from the roots when the main stem dies, so the species has not yet become extinct. However, the stump sprouts rarely reach more than 20 ft in height before blight infection returns. [6]

American Chestnuts getting a head start at the Atlanta History Center

American Chestnuts getting a head start at the Atlanta History Center

And then in 198 the American Chestnut Foundation began a serious program aimed at restoring the American Chestnut.  The goal was to breed blight resistance from the Chinese chestnut tree into the American chestnut tree, while maintaining the American chestnut’s characteristics.  Independent scientific reviews have verified that the foundations work over the last 25 years to restore the American Chestnut to its native habitat in the United States  is being accomplished through their breeding program. [3]

The American Chestnut Foundation has a very active chapter here in Georgia.  If you join their organization at the ‘Seed’ level, you will receive 4 of their blight-resistant seeds. [1]

The South Fork conservancy has planted American Chestnuts along the Confluence Trail and the Atlanta History Center has planted them in the meadow near the Swan House.

Identification and Description

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A shoot with fall foliage taken in November in North Georgia – photo: Biosthmors

The American Chestnut can be best identified by the larger and more widely spaced saw-teeth on the edges of its leaves, as indicated by the scientific name dentata, Latin for “toothed”.  The leaves, which are 5.5 – 8 inches long and 3 – 4 inches broad, also tend to average slightly shorter and broader than those of the Sweet Chestnut. [6]

The blight-resistant Chinese Chestnut is now the most commonly planted chestnut species in the US, while the European Chestnut is the source of commercial nuts in recent decades.  It can be distinguished from the American Chestnut by its hairy twig tips which are in contrast to the hairless twigs of the American Chestnut.  The chestnuts are in the beech family along with beech and oak, but are not closely related to the Horse-chestnut, which is in the family Sapindaceae. [6]

The American chestnut is a prolific bearer of nuts, usually with three nuts enclosed in each spiny, green burr, and lined in tan velvet. The nuts develop through late summer, with the burrs opening and falling to the ground near the first fall frost. [6]

Supported Wildlife and Other Uses

The American chestnut was a very important tree for wildlife, providing much of the fall mast for species such as white-tailed deer and wild turkey and, formerly, the passenger pigeon.  Black bears were also known to eat the nuts to fatten up for the winter. The American chestnut also contains more nitrogen, phosphorus, potassium and magnesium in its leaves when compared to other trees that share its habitat. This means they return more nutrients to the soil which helps with the growth of other plants, animals, and microorganisms. [6]

Adapted to hardiness zones:      hardy to zone 5.   Atlanta is zone 7b

References and Additional Information

[1]  The Georgia Chapter of the American Chestnut Foundation
[2]  The Georgia Chapter of the American Chestnut Foundation: Restoring the American Chestnut Tree
[3]  The American Chestnut Foundation: History of The American Chestnut Foundation
[4]  The South Fork Conservancy: Confluence Trail  (see Chestnut Restoration)
[5]  The Atlanta History Center
[6]  Wikipedia: American Chestnut
[7] Lady Bird Johnson Wildflower Center: Castanea dentata
[8] Missouri Botanical Garden: Castanea dentata