Woodsense: Spotlight on American Chestnut

A blight killed off most of these massive beauties decades ago. But woodworkers still enjoy working with salvaged chestnut, and there is hope on the horizon for the species’ recovery.

AMERICAN CHESTNUT: RECOVERING A LEGEND

“Chestnuts roasting on an open fire. Jack Frost nipping at your nose.” We all know these traditional Christmas lyrics, but the American chestnut tree offered much more than a fading seasonal memory. When there was an abundance of these large trees, the sweet chestnut was a cash crop for many eastern Americans. The nuts were stored and eaten year-round by humans and animals. The wood of the chestnut is compared to the western redwood. It is relatively lightweight, but strong and easily worked with hand and power tools. It is also resistant to decay. Its primary use was for house and barn sidings, fences and poles. In areas where the tree was plentiful, the wood was used for anything from fine furniture to fuel for the fireplace. Chestnut was also a major resource for the leather industry. In some areas, half of the tannin used to make leather came from the chestnut tree. Another industry based on the chestnut was charcoal making. American chestnut and its two cousins, the Chinese and European chestnut, belong to the beech family. This family consists of about 400 species of trees and shrubs, with approximately 50 of them in North America. The most recognized are the oaks, beeches and chinkapins. 

Early times                                                    

The native growth range of the American chestnut covered a large part of the eastern U.S., with heavy concentration  long the Appalachian Mountains from New England to northern Georgia. It could adapt to a variety of site  conditions, but preferred sandy loam. The flowers of the chestnut appeared in June through July with creamy-yellow blossoms. Some mountain ranges were so heavily populated with the tree, some people said they looked like they were covered in snow. The average Chestnut tree grew to a height of 120' with a diameter of 7'. Old photographs and stumps show trees 20' in diameter. The lumber cut from one of these massive logs filled an entire railroad car.

The plight of the chestnut

A bark disease called chestnut blight, caused by Cryphonectria parasitica, was first discovered in the Bronx Zoo in New York in 1904. These fungus spores are carried by air, insects and birds and enter the tree through cracks and wounds in the bark. The disease spreads inside and girdles the tree. Death above the infected area occurs in two to 10 years. The root system stays alive and new sprouts appear, but are killed again as soon as the new tree reaches a certain age. The blight spread so rapidly that despite federal, state and local efforts, most of the chestnut trees where infected by 1930. Because of the wood’s high resistance to decay, dead trees continued to stand for up to two decades. Many areas were called ghost forests. During the dying stage and after the trees where dead, they became prime targets for insect attacks. A particularly virulent attack came from the two-lined chestnut borer, Agrilus bilineatus. Most of the harvest of dead trees was punctured with wormholes, but still sound and used as building material in all kinds of applications. By the 1950s, most of the chestnut was harvested and only a few isolated, unreachable logs remained on the ground throughout its growing range. Wandering deep into the national forests of the eastern US, one might still find a chestnut tree on the ground, covered with moss. Many efforts were made to save the tree and breed a blight-resistant strain. By 1960, most state and federal programs had been halted. A private, nonprofit organization, The American Chestnut Foundation was formed in June 1983 by a group of scientists and concerned citizens. The organization wishes to breed the American chestnut blight with the blight-resistant Chinese chestnut using the “backcross method,” a method of genetic modification proven in crops, but never used on trees. Many cooperating farms are now tendering the fourth generation of chestnut trees. It is estimated that by 2013, a reforestation of a blight-resistant American chestnut will be available. American chestnut is a ringporous hardwood that resembles red oak and white ash in grain and texture, but is much softer. Its color ranges from grayish brown to brown and develops a rich patina with age. Most available chestnut lumber is wormy, which gives it a rustic  appearance. It works easily with hand and power tools, but splits easily. Screws must be predrilled. All the lumber available today is reclaimed from home sites or other buildings. The average price range is from $5 to $10 per board foot for this American legend.

 

—Udo Schmidt is a contributing editor to Woodcraft Magazine.

 

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