US Army Corps of Engineers
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American chestnuts to take root at Green River Lake

Published Dec. 18, 2014
Eric Gracey, Kentucky Division of Forestry, points out a two-year-old American chestnut stump sprout in Fort Knox, Ky.

Eric Gracey, Kentucky Division of Forestry, points out a two-year-old American chestnut stump sprout in Fort Knox, Ky.

Some of the American chestnut stump sprouts found at Fort Knox, Ky., will be transplanted to the new Germplasm Conservation Orchard at Green River Lake.

Some of the American chestnut stump sprouts found at Fort Knox, Ky., will be transplanted to the new Germplasm Conservation Orchard at Green River Lake.

Editor's note: The American chestnut, once ubiquitous over millions of acres of eastern hardwood forests, was virtually wiped out in the early 1900s when a fungus known as chestnut blight was brought to the United States on imported Asian chestnut trees. While American chestnut trees continue to sprout from old stumps and root systems, the blight prevents them from reaching maturity. In recent decades, organizations like the American Chestnut Foundation have worked to restore the population by cross-breeding American chestnut trees with the blight-resistant Chinese chestnut.

The Kentucky chapter of the American Chestnut Foundation (TACF) is working with the U.S. Army Corps of Engineers (USACE) to develop a Germplasm Conservation Orchard (GCO) for the American chestnut tree at Green River Lake in Taylor County, Kentucky. A GCO is a repository for pure American chestnut gene sources. Specifically, this GCO is to be a source for genetic material from the Knobs Physiographic Region in central Kentucky. 

Stump sprouts can be transplanted to the site, nuts from mature native trees can be planted and cuttings can be grafted and planted in the orchard. Once in the orchard, trees can be nurtured with fertilizer, water and insecticides and fungicides while they grow in full sunlight. The goal is to protect the trees and encourage them to mature to flowering, at which point pollen can be gathered from them or brought to them to create new genetic lines for Kentucky’s backcross breeding program. After providing new genetic breeding lines, these trees can continue to be cared for in order to provide a source of pure American nuts. As the Kentucky chapter of TACF develops backcrossed lines, these trees will be introduced back into the forests of Kentucky.

Kentucky chapter TACF members Tim Sheehan, Matt Strong, Kerrin Hester, Rick Caldwell and Jimmie Sizemore, along with Larry Lemon, Green River Lake, Keith Chasteen, Louisville District operations division, members of Kentucky Division of Forestry and U.S. Army personnel from Fort Knox have searched for American chestnut trees on Fort Knox with some success. The primary search area is a unit where thinning and harvesting activities occurred in 2012. The resulting increase in sunlight to the forest floor has promoted rapid growth of stump sprouts. After two growing seasons, the sprouts can now readily be found within the forested environment.

In February, volunteers will return to Fort Knox to dig some of the sprouts that have been found. The sprouts will then be transported to Green River Lake to be planted immediately. Many known sprouts will be left at the Fort Knox site so that the natural chestnut source is not completely removed. However, due to chestnut blight, it is not anticipated that these trees will reach flowering maturity in nature. 

The Green River Lake location is approximately half an acre. Each tree will be planted in a 20’ x 20’ plot, providing space for approximately 48 trees. The Kentucky chapter of TACF will fund an electric fence for the orchard to keep deer away. Some funds were raised through a silent auction at the Kentucky TACF chapter’s annual meeting at Lake Cumberland Aug. 23, 2014. The remaining funds were approved by the chapter’s board members during the quarterly board meeting in November 2014. These funds come from portions of memberships and donations made to the Kentucky chapter.

As other Knobs Region genetic sources are found, they can be used in the Green River Lake GCO to further develop backcross lines from within this region of Kentucky.