When botanists were grappling with the harsh realities of the arrival of the emerald ash borer to U.S. forests, most referenced the devastation that might come to ash trees in terms of another native tree, all but wiped out by a blight. That tree was the American chestnut, Castanea dentata. Scientists now have reason to hope that the majestic trees, once widespread throughout North America but virtually eliminated by the Asiatic blight fungus Cryphonectria parasitica, formerly known as Endothia parasitica, might return blight resistant.

“We are right on the cusp of seeing the results of our work to develop a tree resistant to blight, but that looks and grows like American chestnut,” said Bryan Burhans, president and CEO of The American Chestnut Foundation (TACF). Burhans added it has taken some 26 years to get to this point, “close to restoring something that we thought was lost forever.”

A nonprofit organization dedicated to restoring the American chestnut to its native eastern forests, TACF’s work has been a painstaking effort that involved crossing the tall American chestnuts with the much shorter, blight-resistant Chinese chestnuts, planting them and waiting for the seedlings to grow — a time frame of 6 to 7 years. TACF crossed the two and then back-crossed for more than six generations. The first set of intercross progeny from the third backcross was planted in 2002. Progeny from the second intercross, considered the first line of blight-resistant American chestnuts, were recently planted in Virginia, Tennessee and North Carolina.  

Fred Hebard, TACF’s staff pathologist, said they won’t know for certain that the trees are a “success,” that is, close to the original American chestnuts, for roughly 50 years, the time it takes for a chestnut tree to grow to 100 feet. He said they have been encouraged by their progress to date and will continue planting trees in forests and monitoring their progress, along with the trees planted at TACF’s research farm in Meadowview, VA. “It is a continuous process of evaluation,” said Hebard, who some refer to as the American chestnut’s Johnny Appleseed. Hebard said they hope to continue releasing large numbers of trees into the woods in the next few years.

Beloved Species
Asked why American chestnuts are so beloved, Burhans said he believes it is because American chestnuts were a big part of our culture.
 
“Historically, American chestnuts were the dominant tree, representing 25 to 50 percent of trees in Appalachian and eastern forests. They were fast growing trees that grew to great dimensions, often 5 to 8 feet in diameter, earning them the nickname ‘redwoods of the east.’ Chestnut trees were extremely important to early settlers because they produced a mast crop, each and every year,” said Burhans. “It [also] was extremely valuable as a fast-growing tree that offered lumber that was relatively light, but with the strength of oak. Because we didn’t keep track of its contribution to wildlife then, we can never know what we lost when we lost American chestnuts.”

Chestnuts belong to the genus Castanea, which is comprised of 12 deciduous trees closely related to the beech and oak families. While most of the other species have lived long, healthy lives, some 40 billion American chestnut trees were all but decimated by a fungus believed to have been brought into the United States in the late 1800s on exotic plants and trees, according to TACF.

Chestnuts were prized for a number of reasons. The trees yielded lumber that was used to build homes, as well as furniture, paneling, cabinetry, musical instruments and caskets.

Chestnut lumber is still used today, however the material comes from fallen trees or reclaimed lumber typically damaged by insects. The affected lumber is sold in various grades as wormy chestnut for use in furniture, cabinetry, picture frames, flooring and more.

Debra Russell, sales representative for Mountain Lumber in Ruckersville, VA, sells reclaimed “antique” chestnut lumber. “We get material from barns, fences and other sources, typically from structures built more than 100 years ago. Some of the chestnut lumber is defect-free but most is wormy. Wormy chestnut is the most popular chestnut with our clients, who like the rustic look and character of the honey-colored wood,” she said.

“We remill it after kiln drying it up to 140 degrees for 48 hours. Material can look clear of infestation, but this ensures that any bug larvae is removed,” she added.

Family Name: Castanea dentata of the Family Fagaceae. Common Names: American chestnut, chestnut, wormy chestnut Height/Weight: The average height for American chestnut is 100 feet tall. The average weight is 30 pounds per cubic foot, with a specific gravity of 0.48. Properties: Wormy chestnut has a low bending strength and a medium crushing strength. The heartwood is durable; however, the sapwood is susceptible to attack by the powder post beetle and common furniture beetle. The wood is easy to work with both hand and machine tools, and nails and glues well. It is liable to stain blue when in contact with metals.