The Quest to Bring Back the Chestnut Tree

In 2011, a tornado ripped across southern Massachusetts, destroying homes and buildings in several towns. The storm also leveled woodlands along its path, including a wide swath of forest on the slopes of Mount Ella.

A few years later, seventh-grade teacher Jesse Greene went hiking on that mountain. In an area cleared by the tornado, thousands of small trees had sprouted. Greene recognized them—and he was stunned! The young trees were American chestnuts. This species had all but disappeared decades ago after a disease known as chestnut blight wiped them out.

Greene knew that the young saplings would survive only a few years before the blight killed them too. So he teamed up with fellow science teachers Kristin Daley and Cassie Amadio at Tantasqua Junior High School in Fiskdale, Massachusetts. The teachers called a meeting with their students and told them about the problem. The students decided to use this window of opportunity to try to help. In 2016, the school started the Tantasqua Chestnut Project. With support from experts at The American Chestnut Foundation (TACF), the students have been working to grow blight-resistant chestnuts in hopes of saving the trees.

In 2011, a tornado ripped across southern Massachusetts. It destroyed homes and buildings in several towns. The storm also leveled woodlands along its path. On the slopes of Mount Ella, it wiped out a wide strip of forest.

A few years later, Jesse Greene went hiking on that mountain. The seventh-grade science teacher saw the area cleared by the tornado. Thousands of small trees had sprouted there. Greene recognized them, and he was stunned! The young trees were American chestnuts. This species had nearly disappeared decades ago. A disease called chestnut blight had wiped them out.

Greene knew that the young trees would probably survive only a few years. Then the blight would kill them too. So he teamed up with Kristin Daley and Cassie Amadio. They’re his fellow science teachers at Tantasqua Junior High School in Fiskdale, Massachusetts. The teachers called a meeting with their students and explained the problem. The students decided to help. In 2016, the school started the Tantasqua Chestnut Project. Since then, the students have been working to grow blight-resistant chestnuts. Their goal is to save the trees. Experts at The American Chestnut Foundation (TACF) are helping them.

In the 1800s, an estimated 4 billion American chestnuts filled forests across the Eastern United States (see Past Chestnut Range). They were known as the Redwoods of the East because of their huge size. Some trees reached up to 3 meters (10 feet) in diameter. Their nuts provided food for wildlife, livestock, and people. And because chestnut wood is rot-resistant, it was often used to construct buildings. “I heard stories about the chestnut tree from my great-grandma,” says EleanorPitcher, who is now a senior working with the Tantasqua Chestnut Project.

American chestnuts once filled forests across the Eastern United States. In the 1800s, about 4 billion of them were growing (see Past Chestnut Range). They were called the Redwoods of the East because of their huge size. Some trees reached up to 3 meters (10 feet) in diameter. Their nuts provided food for wildlife, livestock, and people. Chestnut wood is rot-resistant, so it was often used in buildings. “I heard stories about the chestnut tree from my great-grandma,” says Eleanor Pitcher. She is now a senior working with the Tantasqua Chestnut Project.

But trouble arrived when another species of chestnut was imported to the U.S. from Asia in the late 1800s. The trees, known as Chinese chestnuts, carried a dangerous fungus—an organism that lives by feeding on organic material. The trees from Asia were resistant to this fungus, known as chestnut blight. American chestnuts were not. The fungus swept through the American population, killing the trees from the trunk up, while leaving their root systems intact. By the 1950s, the American chestnut was functionally extinct. The species still existed, but because of the blight, new trees couldn’t grow large enough to produce another generation. Without help, the tiny American chestnuts Greene spotted on Mount Ella would face the same fate.

When the tornado cleared away vegetation on Mount Ella, it gave sprouts the chance to shoot up from surviving chestnut tree roots, says biologist Jared Westbrook, TACF’s director of science. But when this happens, sprouts don’t usually live long. “If they do grow tall, they will get the blight and die back,” says Westbrook.

But trouble arrived in the late 1800s. Another species of chestnut was imported to the U.S. from Asia. These trees were called Chinese chestnuts, and they carried a dangerous fungus. This type of organism lives by feeding on organic material. The trees from Asia were resistant to this fungus, called chestnut blight. American chestnuts were not. The fungus swept through the American population. It killed the trees from the trunk up, but it left their root systems in place. By the 1950s, the American chestnut was functionally extinct. The species still existed. But new trees couldn’t grow large enough to produce another generation. The blight killed them first. Now Greene had spotted tiny American chestnuts on Mount Ella. Without help, they would face the same fate.

The tornado had cleared away vegetation on Mount Ella. That gave sprouts a chance to shoot up from surviving chestnut tree roots, says biologist Jared Westbrook. He’s TACF’s director of science. But when this happens, sprouts don’t usually live long. “If they do grow tall, they will get the blight and die back,” says Westbrook.

To help restore the trees, experts at TACF have been crossbreeding the American chestnut with the blight-resistant Chinese species. By doing this, the organization creates a hybrid, or mix of two different species. The hybrid plant gets half of its genome—or complete set of hereditary material—from each species. Then those hybrids are bred with other American chestnuts. “Over multiple generations, we dilute out the Chinese chestnut genome and bring in more American chestnut genome,” says Westbrook. After three decades of breeding, the result is a tree that’s mostly American chestnut—but with some blight resistance.

The Tantasqua students volunteered to add the young trees on Mount Ella to TACF’s breeding program. In the spring of 2016, they hiked up the mountain and covered the female flowers on the trees with paper bags. This would prevent powdery pollen grains released by male flowers from fertilizing them. Later, the students returned to pollinate the mature female flowers by dipping them in pollen from TACF hybrid trees. That way, the resulting hybrid chestnuts would have genetic material from both a Mount Ella wild American chestnut and a disease-resistant hybrid.

Experts at TACF are trying to restore the trees. They’re crossbreeding the American chestnut with the blight-resistant Chinese species. By doing this, they create a hybrid. It’s a mix of two different species. The hybrid plant gets half of its genome from each species. The genome is its complete set of hereditary material. Then those hybrids are bred with other American chestnuts. “Over multiple generations, we dilute out the Chinese chestnut genome and bring in more American chestnut genome,” says Westbrook. After three decades of breeding, they have a tree that’s mostly American chestnut. But it has some blight resistance.

The Tantasqua students volunteered to help. They added the young trees on Mount Ella to TACF’s breeding program. In the spring of 2016, they hiked up the mountain. They covered the female flowers on the trees with paper bags. This would prevent pollen from fertilizing them. Powdery pollen grains are released by male flowers. Later, the students returned to pollinate the mature female flowers. They dipped them in pollen from TACF hybrid trees. The result would be hybrid chestnuts. They would have genetic material from both a Mount Ella wild American chestnut and a disease-resistant hybrid.

In the fall, the students gathered nuts produced by these trees. The following spring, they planted them on their school campus. Their orchard currently holds 200 young American chestnuts. Students have also helped plant 500 hybrid trees provided by TACF on Mount Ella, where they’ll hopefully cross-pollinate with wild ones.

These trees produced nuts in the fall, and students gathered them. The next spring, they planted them on their school campus. Their orchard now holds 200 young American chestnuts. TACF also provided 500 hybrid trees. Students helped plant them on Mount Ella. Hopefully, these trees will cross-pollinate with wild ones.

Students helping with the longterm project on Mount Ella take steps to ensure new trees survive. Eleventh-grader Nathan Dietz says, “When planting a seed, we make sure there are no other plants or outside factors that affect it.” To do this, students clear an area of ground, dig a hole for the seed, and place a mat around the hole to prevent weeds from growing. Then they place a plastic tube around the seed so animals don’t eat it.

Students work to help the new trees survive in the long-term project on Mount Ella. Eleventh-grader Nathan Dietz says, “When planting a seed, we make sure there are no other plants or outside factors that affect it.” To do this, students clear an area and dig a hole for the seed. They place a mat around the hole to prevent weeds from growing. Then they place a plastic tube around the seed. That stops animals from eating it.

This past summer, the trees didn’t get enough rain. Students cleared a path up the mountain so Louis Desy, a founding Tantasqua project member, could deliver water with his truck. “The hardest part for me is waiting,” says Desy, who’s now a sophomore in college. The trees will take decades to mature. Until they do, no one knows how well they’ll resist the blight.

But Tantasqua Chestnut Project members know their efforts will be worth it if the trees are restored. Ninth-grader Noah Clark says, “I like the idea of being able to come back to see this work I’m doing 30 years from now and say, ‘I helped with that.’”

Last summer, the trees didn’t get enough rain. So students cleared a path up the mountain. Then Louis Desy delivered water with his truck. He’s a founding Tantasqua project member and is now a sophomore in college. “The hardest part for me is waiting,” says Desy. The trees will take decades to mature. Until then, no one knows how well they’ll resist the blight.

But Tantasqua Chestnut Project members hope the trees will be restored. Then their efforts will be worth it. Ninth-grader Noah Clark says, “I like the idea of being able to come back to see this work I’m doing 30 years from now and say, ‘I helped with that.’”