Can I Eat Chestnuts?

Q:  I’ve noticed roasting chestnuts mentioned in older Christmas songs and movies. I think there is some kind of chestnut tree in my yard. Are the nuts edible? N.S.

A: If you have a true American chestnut tree (Castanea dentata) in your yard, the fruits are edible and, according to many sources, quite tasty. But be careful, if your tree is a horsechestnut the nuts are poisonous. Before eating any plants, make sure you identify them correctly.

 American chestnut trees are very rare. Once a major part of forests in the eastern United States, the large stately trees were valued for their high quality, beautiful wood, which was often used in furniture. The nuts are reported to be very sweet and flavorful. In the early 1900’s chestnut blight was discovered in New York.  In fifty short years the fungal disease nearly wiped out all American chestnut trees. You can occasionally find American chestnut trees in Wisconsin. These remaining trees are not resistant or immune to blight but too geographically isolated to be exposed to the disease.

 Leaves of American chestnut are 5-8 inches long with prominent teeth along the edges. The 2 to 3 inch round fruits are covered with “prickles”. Inside are two or three nuts.

 Non-native Chinese chestnut (Castanea mollissima) is related to American chestnut and resistant to chestnut blight. Although not common, it is planted as a large shade tree in the United States. The leaves and fruits are similar to American chestnut. The nuts are edible but not quite as sweet as its American cousin. The American Chestnut Foundation is developing hybrids of American and Chinese chestnuts with blight resistance.

 Horsechestnuts, and their American cousin buckeye, are poisonous to humans. These members of the genus Aesculus have palmately compound leaves. This type of leaf looks like a spread hand, in which the bases of the five to seven leaflets meet together one point on the petiole (leaf stem).

 Horsechestnut and buckeye fruits are similar in size to chestnut fruit but not as spiny or prickly.  The showy flower clusters are conical.  European horsechestnut (Aesculus hippocastanum) and, to a much lesser extent in Wisconsin, Ohio buckeye (Aesculus glabra) have been planted as street and landscape trees. Red buckeye (Aesculus pavia) and bottlebrush buckeye (Aesculus parviflora), which is a large shrub, are also used in Wisconsin landscapes.

 Kenosha News, December 22, 2011
Barb Larson, Horticulture Educator
Kenosha County UW-Extension
262-857-1945
Home Hort Hotline:  262-857-1942