STRONG SAPLING: This American chestnut tree planted in April 2020 at Mapleton Preserve in Kingston has taken well and is showing new growth. (Photo courtesy of Karen Linder)

By Wendy Greenberg

The now-scarce American chestnut tree could be making a comeback in New Jersey.

When a sapling was planted in April 2020 at Mapleton Preserve in Kingston, in lieu of a planned Arbor Day public planting that was canceled due to the pandemic, it was a step toward re-establishing the majestic American chestnut tree with hybrid saplings that may resist a devastating blight.

“We wanted to plant the little chestnut tree at Mapleton before it started coming out of dormancy in mid-April or so,” explained the planter, Michael Aucott of Hopewell, the site of similar plantings. “The best time to transplant a tree is when it is dormant, especially when transplanted as a bare-root tree, as the Mapleton tree was.”

The tree is doing well, reports Karen Linder, a trustee of Friends of Princeton Nursey Lands (FPNL), which tried to hold the Arbor Day event. She said it appears to have a lot of new growth and there are no visible problems.

Aucott, a research scientist who coordinates the monitoring and management of 20 orchards which include 5,000 trees, part of The American Chestnut Foundation’s (TACF) breeding program, is a consultant on energy and air pollution issues. He retired from the N.J. Department of Environmental Protection in 2012.

Aucott said he has been interested in chestnut trees since he began a leaf collection as a fifth-grader in the Philadelphia suburbs, and could not find the rare chestnut tree.

“One day I was at a friend’s house and found one; it was a sprout from an old stump,” he said. “I got a leaf, which I added to my collection. I put it all aside until 15 years ago, when my son, a woodworker in Asheville, N.C., which happens to be the TACF headquarters, produced some furniture from chestnut timbers he found in an old barn and put his work in a show. He encouraged me to renew my interest in this tree.”

Aucott said he went to one TACF meeting, and that is all it took. “I became heavily involved,” he said.

Replenishing the chestnut tree in New Jersey, and the country, is not an easy task, Aucott explained. The tree, native to New Jersey, was widespread in the 1800s — when many towns named a Chestnut Street — but disappeared quickly after a blight that began in the early 1900s.

In the late 1800s people were importing trees from Asia which harbored the fungus, which causes a bark disease. “The Asian trees were resistant,” he said, “but the American chestnut was not. Spores spread and the blight took off.”

The blight was discovered at the New York Zoological Garden in 1904, and by the 1940s it reached all chestnut trees, “leaving few in its wake,” said Aucot in previous interview.

Although the trees are considered functionally extinct, sprouts do grow from root collars until about 10 to 20 feet, but as the trees get older and the bark cracks, the blight kicks in. The stump again sprouts, and the process continues, but the tree does not reproduce because it never reaches the forest canopy and cannot flower without full sun, Aucott explained.

The hybrid trees that are being planted today are a cross with the Asian chestnut, for its resistance, and American, for the height. TACF is using a “backcrossing” breeding technique that involves successive crosses and selection, with the hope of producing a tree with the blight resistance of the Asian trees and the tall growth and other characteristics of the American chestnut. The process takes seven or eight years, for each generation, and has been underway since the early 1980s.

Aucott recently noted that TACF is increasingly optimistic that a genetically engineered tree that is 100 percent American chestnut except for an added gene from the wheat plant will soon be approved for public distribution. If approved, regionally-adapted surviving American trees could be pollinated with pollen from these trees, producing highly blight-tolerant trees.

There are over 100 chestnut trees now growing in the area, including trees planted in Hopewell Township at the Fiddler’s Creek Preserve, demonstration plantings at Hopewell Valley Regional School District elementary schools, a demonstration planting at Hopewell Township’s Woolsey Park, a planting at D&R Greenway’s St. Michael’s Preserve, and the Foraging Forest project of the Sourland Conservancy in Hopewell Borough.

The tree planted at Mapleton is a second generation hybrid, an American and Asian cross which is about five years old. According to Aucott, it should have some blight resistance, although there is no guarantee that it will not eventually succumb. “But with luck it will grow well for quite some time and reach a good size,” he said.

The FPNL group, formed in 2000, is devoted to preserving and protecting the historic former Princeton Nurseries Kingston site. The group continues to work with the Mapleton Preserve Commission, South Brunswick Township, the D&R Canal State Park, the state of New Jersey, and other local and regional organizations to assure the preservation, restoration, and interpretation of the land and buildings once owned by Princeton Nurseries. In 2005, through a partnership including South Brunswick Township, Princeton Nurseries, and the New Jersey Department of Environmental Protection’s Green Acres program, more than 240 acres of the former wholesale nursery were preserved, and the 53-acre property, known as Mapleton Preserve, is now owned jointly by the New Jersey Green Acres program and South Brunswick Township.