THE RETURN OF THE AMERICAN CHESTNUT TREE

High in the forest canopy, tall trees with furrowed bark, adorned with sawtooth-edged leaves, are full of creamy white blossoms that will produce a fall carpet of sweet brown American chestnuts. It’s every arborist’s dream, but is it a dream of America’s past—or its future?

If any tree can represent both, it is the American chestnut (Castanea dentata). A century ago it stood as a vital natural resource, common in forests of the eastern United States, but the chestnut was rendered functionally extinct by an early twentieth-century blight. By 1940, these once-stately trees existed only in a diminished shrub form.

Ever since its disappearance, people have been chasing the dream of restoring to the Eastern forest canopy a blight-resistant American chestnut tree. This regional restoration project draws in scientists, ecologists, plant breeders, and tree-loving volunteers from all over, including the River Towns. Among them is Jim Searing of Solebury, a member of the board of The American Chestnut Foundation. “The return of the American chestnut in the River Towns region is a community story,” Searing says. “Local volunteers, landowners, and conservation organizations are stepping forward as citizen scientists, helping rebuild a vital component of farms, fields, and forests that was lost but not forgotten. And that’s how we rebuild and move forward, with optimism and persistence, recognizing this is a multigenerational effort.”

Mike Aucott is a leader in the River Towns’ chestnut restoration community. A resident of Hopewell Township and a PhD environmental scientist formerly with the New Jersey Department of Environmental Protection, Aucott is now a consultant. He speaks and writes frequently about the restoration of the chestnut, he organizes plantings, and he tends 800 chestnut trees on two acres of his thirty-six-acre orchard in rural Potter County, in north-central Pennsylvania. He’s also a member of the Pennsylvania/New Jersey chapter of The American Chestnut Foundation.

Aucott describes restoration efforts as a “guided evolutionary rescue of the American chestnut.” If a resistant tree is a dream, it is one rooted in the fundamental process of life. Asian chestnuts naturally evolved resistance to the blight. The restoration project uses a panoply of techniques, both ancient and modern, to mimic what nature does, only at warp speed.

Aucott put this evolutionary booster to a practical test with a major planting at Fiddler’s Creek Preserve near Washington Crossing State Park in Titusville. In 2018 and 2019, working with Friends of Hopewell Valley Open Space, which owns the preserve, and the Hopewell Township Environmental Commission—Aucott was a longtime member—he organized plantings of about 200 American chestnuts on a forty-acre plot, part of a larger forest regeneration project that includes fencing to keep out deer.

There are an estimated fifty to sixty surviving trees at Fiddler’s Creek. Planted in groups of ten, scattered around the site, the young trees stretch cautiously above the surrounding goldenrod and blackberry brambles and tree saplings. “They’re starting to get to the age where chestnuts bloom and produce nuts,” Aucott says.

The wait is on—will they survive the blight?

The larger question is: Why? Why do so many people care so much about a long-lost tree? In his 1950 book, A Natural History of Trees of Eastern and Central North America (Houghton Mifflin), the naturalist Donald Culross Peattie wrote, “All words about the American Chestnut are now but an elegy for it.”

Consider this story not an elegy, but an ode.

Before the blight, an estimated four billion American chestnuts stood from Maine to Mississippi and west to Ohio, Indiana, and Ontario. The tree grew 100 feet or taller in forests, with a diameter up to ten feet. It was fast-growing and long-lived. It preferred a moderate climate, on moist, well-drained slopes. In some Eastern forests, the American chestnut was the dominant species.

The chestnut had a miraculous-seeming capacity for resurrection, an ability to sprout from stumps, which adapted it to areas of intensive logging. Chestnut-dominated stands formed about half of second-growth forests in New Jersey and Pennsylvania.

Over the years the tree gave its name to innumerable Chestnut Streets, along with Chestnut Hills, Chestnut Groves, Chestnut Ridges, and so forth. “Chestnuts roasting on an open fire,” the opening line from “The Christmas Song,” co-written eighty years ago by Mel Tormé and most famously recorded by Nat King Cole, remains among the most recognizable lyrics in American song. Researcher Songlin Fei found that “chestnut-related place names have a strong fidelity to the known natural range of the species…. The abundance of chestnut-related place names … may have a strong relation to local abundance of this tree … because it was important to local cultures and economies.”

American chestnut trees had economic, ecological, and cultural value that set them apart. The nuts provided food for wildlife (deer, turkeys, birds, squirrels, and many other species). A mature tree can produce 6,000 nuts annually. They’re produced reliably every year, unlike acorns, beechnuts, and hickory nuts, which form abundantly in a “mast year” and sparsely in other years.

America’s indigenous people revered the chestnut. Its leaves were used medicinally, its nuts were eaten, its bark was used for siding. They encouraged chestnut growth, even if inadvertently, through land management practices such as intentional burning.

European settlers, too, loved the nuts, which were extolled as plump and sweet. Stories abound of “chestnutting”: excursions to groves by a family or community to gather the bounty of nuts by raking fallen nuts or vibrating the branches to drop them. Around Thanksgiving and Christmas, train cars piled high with nuts harvested in rural areas chugged into Eastern cities, supplying many a holiday celebration.

Chestnut wood—straight-grained, rot-resistant, and easily split—was a favored source of fence timber. Early settlers used logs for cabins. Bowman’s Hill Wildflower Preserve in Solebury has a chestnut cabin, built in 1935 by workers from the Civilian Conservation Corps and the Works Progress Administration, from logs harvested on the preserve. The chestnut supplied millions of railroad ties and utility poles. And it was popular for furniture and cabinetry. “The seemingly endless utility of the American chestnut made it perhaps the nation’s most important tree species by the beginning of the twentieth century,” historian Eric Rutkow wrote in American Canopy: Trees, Forests, and the Making of a Nation (Scribner, 2013).

The blow that struck the American chestnut fell as swiftly and thoroughly as a logger’s axe. In 1904, a deadly infection of the chestnut was discovered in New York’s Bronx Zoo. Caused by the fungal pathogen Cryphonectria parasitica, the blight produces spores that are spread by wind, water, and wildlife. By 1914 it was found in eleven states.

The fungus had likely arrived on imported Japanese chestnut trees, whose popularity as an orchard and landscape tree had soared in the late nineteenth century. Both are resistant to the blight. To make matters worse, the chestnut simultaneously faced a second imported threat in the southern part of its range—Phytophthora root rot, which kills the tree’s roots.

Desperate measures ensued as forest managers sought to contain the blight: healthy trees were felled along with diseased trees, to create buffer zones. Their removal was later seen as a colossal error, since it prevented any opportunity for natural resistance to operate.

By 1940, the American chestnut had disappeared from the canopy of the Eastern forest. Oaks and maples largely replaced chestnuts in the forest overstory.

It is impossible to exaggerate the blight’s impact. As expressed in Mighty Giants, The American Chestnut Foundation’s 2007 anthology, “Chestnut blight remains the most destructive disease known for any host, including trees, other plants, animals, and humans.”

Blight kills the chestnut’s trunk and branches, causing the tree to die back to its roots. The root system, though, is not killed. Chestnuts’ ability to regrow from those resilient roots generates stump sprouts that become saplings. With sufficient light, these reborn trees grow vigorously. They can survive for ten to fifteen years, then become susceptible to the blight—still present in the air and soil—and the tree dies back to its roots again. In forests where American chestnuts once flourished, you’ll see these so-called stump sprouts (also known as “ghost trees”), a glimpse of the past.

Although former chestnut-rich forests are uncommon in the River Towns, you can still find ghost chestnuts at Natural Lands’ Mariton Wildlife Sanctuary in Riegelsville, Pennsylvania. “Several remnant rootstocks on the property still produce woody growth, with the most available individual being found at the Chimney Rock/North Fox trail junctions [visible just off the downhill side],” Zane Miller, the preserve’s manager, wrote in an email.

From the time the American chestnut began to vanish, people have harbored hopes that the blight was all a bad dream and the chestnut could be restored to forests. A replacement would need to resist the blight (and root rot) and grow straight and tall to reach the canopy. It should produce massive, reliable nut crops. And it must produce progeny that display these traits. Because the American chestnut occupied such a broad geographic range, restoration would require trees adapted to different climates.

Today there are three main approaches to restoration. One is to build on the blight resistance of the Chinese and Japanese chestnuts by breeding them with American trees. A second is to propagate rare surviving American chestnuts, seeking to pass on blight-resistance to successive generations. A third is genetic engineering, incorporating a gene from wheat into the American chestnut gene.

The more we learn about resistance, though, the more we understand that it’s more complicated than we thought. Says Jared Westbrook, the director of science for The American Chestnut Foundation, “One of the mistakes we’ve made over time with this project is we’ve assumed simplicity.”

Simple substitution was attempted in the 1910s. Could Chinese chestnuts replace the American trees? But the answer was no. Asian trees are resistant, but because they’ve been bred to produce nuts in orchards, they grow slowly and not very tall.

Hybridization came next, beginning a decade later. If pure Asian trees would not fill the American niche, could they be cross-bred with American chestnuts to obtain the desirable characteristics?

Interbreeding chestnuts is no easy feat. It’s all done by hand. The male (pollen-producing) chestnut flower is a long catkin; the female a short bur. Each tree has both types. In nature, wind is the pollinator. Hand-pollinating requires climbing up to the flowers. (For taller trees, a ladder or bucket truck may be required.) Female flowers are bagged, then male flowers’ pollen is collected, and finally pollen is hand-rubbed onto female flowers.

Researchers used pollen from surviving American chestnuts to fertilize Asian trees, then grew hybrid trees from the nuts. But hybrids did not have those critical American chestnut qualities. By 1960, simple cross-breeding had been abandoned.

The American Chestnut Foundation (TACF) is a nonprofit whose goal is to restore the chestnut to its former place in the Eastern forests. The group works through local chapters and with volunteer chestnut growers, planters, and enthusiasts to support planting, breeding, and research. In 1989, the foundation initiated a more complex approach than traditional cross-hybridization, called “backcrossing,” in which Chinese chestnuts are bred with American chestnuts and the progeny inoculated with blight. Those showing strong resistance are bred successively, each time being inoculated with the blight to identify the most-resistant trees. In theory, a fully resistant tree could be produced in six generations.

Backcrossing has been tried in several locations in the River Towns. Beginning in 2002, the Doylestown-based Heritage Conservancy, partnering with local Boy Scouts and the Cooks Creek Watershed Association, planted hybrid chestnuts for The American Chestnut Foundation’s backcross program at the conservancy’s Fuller-Pursell Preserve, in Springfield Township, Pennsylvania. “The orchard is still operating and TACF is still collecting data,” Jim Drennan, the conservancy’s director of science and stewardship, wrote in an email. “The orchard is a mix of hybrid chestnuts [American x Chinese] and pure American.” The trees, some producing nuts, are in a fenced nursery in a hilltop meadow, easily seen along the preserve’s Bluebird Trail.

A small planting of nut-producing hybrid chestnuts can also be seen at Hunterdon Land Trust’s Zega Lockatong Preserve, in a meadow at the beginning of Mimi’s Trail.

A different approach to the restoration of the chestnut tree is to try breeding pure (or almost-pure) American trees from rare survivors. This approach is championed by, among others, the nonprofit American Chestnut Cooperators Foundation (ACCF). Since 1982, the foundation has bred 100 percent pure American chestnuts from a surviving Virginia population, backcrossed to attain high resistance. The first nuts were planted in 1982, and in 2023 the first test of their descendants in a forest setting was planted at the New England Botanic Garden at Tower Hill, in Massachusetts.

The nuts that Aucott planted at Fiddler’s Creek Preserve are descendants of a pure American tree and a hybrid European-American. According to Lake Graboski, TACF’s north central regional science coordinator, “European chestnuts are slightly more resistant to the chestnut blight than American chestnuts on average. This, and hypovirulence [a virus that attacks the chestnut blight], is what has allowed the European chestnut to survive as an agricultural part of Europe.”

Pollen from an old American survivor in Amherst County, Virginia, was used to fertilize the hybrid Kelley tree from Cumberland County, Pennsylvania. The resulting nuts were planted by volunteers from The American Chestnut Foundation in an orchard at Codorus State Park—south of Harrisburg, near the Maryland border—producing seedlings. “The Kelley-Amherst trees average approximately eighty-six percent American although some could have more, or less, American ancestry,” Aucott says. “They closely resemble American chestnuts.”

The nuts from these seedlings were planted at Fiddler’s Creek. Will the trace of European heritage affect their growth rate or height? Time will tell.

In Hopewell Borough, Aucott worked with the Sourland Conservancy to plant twelve Kelley-Amherst seedlings in the Conservancy’s “Foraging Forest” in 2019. All the trees are so far “doing well,” according to Robert Aluck, the stewardship director for the Conservancy. Two were blooming in summer 2026, Aucott says.

In the Princeton area, volunteer Bill Sachs led several 2010 plantings of chestnuts that were fifteenth-sixteenths American and one-sixteenth Japanese. The twenty planted trees had been bred by Sandra Anagnostakis at the Connecticut Agricultural Experiment Station. Three have survived and are producing nuts, according to Steve Hiltner, a local naturalist who has written about the plantings in his blog, Princeton Nature Notes.

In 1955, University of Virginia scientist Ralph Singleton proposed irradiating American chestnut nuts to create mutations, with the hope that one variant trait would be increased resistance. Singleton inspired others to try “mutation breeding.” West Virginia chemist Albert Dietz was a particularly energetic champion of mutation breeding; he arranged for thousands of nuts to be irradiated (at Brookhaven National Laboratory and labs in Virginia and West Virginia), then provided them to volunteers for planting during the 1960s and ’70s.

This approach caught the interest of Tony Guerrero, then co-owner, with his wife, Mary, of Mariton Wildlife Sanctuary. (The sanctuary has been managed for a trust since 1992 by Natural Lands). Guerrero planted irradiated chestnuts in a grove at the sanctuary. Perhaps one mutation was successful, or perhaps it was coincidence, but some of the trees survived. These progeny are still standing at Mariton—and still alive, as attested by Zane Miller.

Genomic sequencing techniques were developed over the last fifty years to determine an organism’s genetic information. Scientists have now sequenced several American and Chinese chestnut trees. This enables more precise identification of genes that support desirable traits.

But, as Jared Westbrook of The American Chestnut Foundation explained to Ira Flatow on an NPR Science Friday podcast, it’s still complicated. “With our backcross program, we assumed two to three genes contribute to resistance,” Westbrook said, “and what we learned when doing the DNA sequencing of our hybrids is that actually hundreds of different parts of the genome contribute to that resistance.”

The American Chestnut Foundation’s current restoration strategy is “recurrent selection.” Westbrook explained it to Flatow as “select the best parents, select better kids, keep going over multiple generations.” Using genomic sequencing, the foundation staff, working with its community of volunteers, breeds together American and Chinese trees for desired traits (still hand-pollinating after all these years). Then, using genomic sequencing again, the foundation selects the best nuts to plant. New techniques to accelerate flowering shorten the time to the next generation. Recurrent genomic selection, Westbrook said, is “for sure going to work.”

Daniel O’Keefe, the president of the foundation’s Pennsylvania-New Jersey chapter, says, “While DNA sequencing is critical to this approach, it’s worth noting that the resulting trees are the result of ‘natural’ breeding methods and are not transgenic.”

So what is “transgenic”? Scientists from the State University of New York College of Environmental Science and Forestry inserted a gene from wheat into the American chestnut genome to try to increase resistance. They developed a tree known as Darling 54. Their research study, released in February, concluded that the trees exhibit strong survivorship and growth form, though they do not grow as tall as non-transgenic chestnuts.

A critical hurdle for these genetically modified trees as forest restoration candidates is regulatory approval. The U.S. Department of Agriculture gave preliminary approval in 2025; reviews are pending by the Food and Drug Administration and the Environmental Protection Agency. On Arbor Day 2026, two Darling 54 trees were planted at the White House.

After more than a century of effort, how close are we to success? Westbrook predicted to Flatow that within seven years—when current RSG-crossbred trees will have produced nuts—there will be enough candidates to start planting trees in forest restoration trials, inoculating them and assessing resistance. He noted it would be a multigenerational effort. “We need to continue this over decades,” Westbrook said. “We need to continue to bring younger people into this effort.”

And who better to bring younger people into the science of chestnut restoration than Mike Aucott? Among the many plantings he’s organized were four demonstrations at Hopewell Township elementary schools in 2019. Students planted Asian, American, and hybrid seedlings for assessment.

Aucott’s passion for growing chestnuts was kindled when he was the age of these students. “When I was in fifth grade, I got interested in collecting leaves. I had read the story of the chestnut. I was looking for chestnuts, looking and looking. One day I was visiting a friend. I remember finding a stump sprout and collecting a leaf. That became the prize in my collection.

“Even when a little kid, I’d collect seedlings and plant them,” he continues. “I’ve always been interested in trees ever since then. I had a little nursery when I was 7 or 8. I got interested in gardening when I was 6 or 7. My grandfather had a garden.… He taught me how to grow vegetables. Trees are an offshoot of vegetable gardening. It’s a seed that turns into a big tree.”

Aucott says he “forgot” about chestnuts until fifteen years ago, when his son’s woodworking project, using salvaged chestnut, triggered his curiosity. He attended a growers meeting organized by The American Chestnut Foundation and got hooked. Now the Pennsylvania farm he and his wife have owned since the 1970s includes a chestnut orchard where he turns seeds into big trees.

He is optimistic that chestnuts will return. “Knowledge about genetics is expanding greatly,” Aucott says, “and many people are using this deeper understanding to save the American chestnut from extinction. This inspires hope for this tree, for other threatened trees, and for the forests of the future.”

Susan Charkes is the author of The Wild Here and Now (Arboreality Press, 2013). More at susancharkes.com