After more than a decade of nurturing, it had come time to infect this 28-acre grove of American elms with a disease that would almost certainly kill them. Dressed in hunter-green muck boots, grey pants, and a brown Nature Conservancy T-shirt, Gus Goodwin knelt down to give the first tree its shot. Using a bamboo stake marked at 12 inches as a gauge, he measured that far off the ground, held his drill at a slight downward angle, and pulled the trigger. ‘We need to create a wound,’ Goodwin, the conservancy’s director of science and technology advancement in Vermont, said as the tool began to whir. He bore an inch-deep hole into the tree, the bit sending shavings spiraling out behind it. Putting the drill aside, he took a blue pipette from his tool box and injected 2 teaspoons of a clear solution containing roughly 100,000 spores of the fungus that causes Dutch elm disease. ‘That’s it,’ he said. ‘Pretty simple.’ One by one, row by row, the plan was to stick nearly all of the 5,300 or so elms at the sprawling site in southern Vermont, save the few that received a squirt of water as a control. In the coming weeks, most of the trees would doubtlessly succumb to the pathogen that has already killed tens of millions of their ancestors and made Ulmus americana an endangered species. The ones that live, however, could help save the species. A research specialist with the University of Vermont records information young elm trees that have been inoculated with Dutch elm disease on May 19, 2026. Jessica Rinaldi / The Boston Globe via Getty Images This project is the most promising attempt yet in the decades-long effort to restore a crumbling pillar of American forests. If successful, it could spawn the largest, healthiest, most genetically diverse population of disease-tolerant elms North America has seen in more than a century. Those trees would provide shade and elegance wherever they cast shadows and support the creatures, like double-toothed prominent moths, specifically adapted to them. ‘Their life is so tightly tied to the species that they evolve to look like the edge of the leaf,’ Goodwin said, explaining how the caterpillar camouflages neatly with the stegosaurus-like ridges along the edge of an elm leaf. ‘If you substitute another species in, you kind of pull the rug out from under that.’ American elms also help mitigate flooding, which climate change is making more frequent, intense, and devastating. It’s a threat that Vermont knows well, having experienced two 100-year deluges since 2023. According to one study, bolstering the state’s floodplains could avoid as much as $1 billion in property damage over the next century. Similar logic applies across New England and beyond. ‘There’s no other floodplain tree that’s shade tolerant, flood tolerant, and long-lived,’ said Goodwin. The hope is to bring that buffer against climate disasters back. If, of course, any of the trees here survive. Read Next The Northeast’s hemlock trees face extinction. A tiny fly could save them. Zoya Teirstein After Goodwin injected his first sapling, he marked it with a dab of orange paint to show that it had been jabbed. He then opened an app detailing this research plot, and looked up the tree. Elm number 439 is the offspring of Valley Forge, a nursery strain bred to be disease-tolerant, and an individual called Damon from the Pioneer Valley of western Massachusetts. Survivor tree 31, as the latter is known, measures more than 7 feet around and is one of about 50 potentially hearty parents represented in this research plot. Those with the most resistant and genetically diverse progeny will be cloned and moved to the new seed orchard of ‘super trees.’ Goodwin also recorded where sprouts, called epicormic shoots, had popped out of number 439. Knowing this was important because, if more of them appeared later, it could be an indicator of stress. With that done, he moved to the next elm, then the next, a trail of orange paint in his wake. In the coming days, as many as six crews would descend on the grove to finish the task. After each tree-tap was registered in the app, the icon went from red to green. ‘I get the satisfaction of watching that dot turn color,’ said Goodwin, who was eager to see which trees would start to die. In a few weeks, trees without resistance would begin to develop symptoms — wilting, discolored leaves, or an outburst of epicormic shoots. Only then would the researchers know if their plan for a reinvigorated army of elms might work. ‘We’re at a really exciting milestone in the project.’ Researchers inject experimental elms with Dutch elm disease at a test site in Benson Vermont. The Nature Conservancy The American elm is remarkable. Its branches arch upward and outward, forming a cathedral-like canopy of green that can stretch more than 100 feet above the forest floor. Each autumn, the leaves turn a vibrant golden-yellow. ‘The elm is a tree which can be distinguished farther off perhaps than any other,’ 17th-century naturalist Henry David Thoreau wrote in his journal. ‘It is beautiful alike by sunlight and moonlight.’ These fecund specimens achieve their mature height and vase-like shape in as little as 15 years and, unencumbered, can live as long as 300. With their expansive native range and a love of moist, fertile soil, the trees used to dominate river valleys and floodplains from the Canadian maritimes to East Texas. For Indigenous populations, they were meeting places, signposts and council trees around which important gatherings revolved. As the New World became America, settlers began clearcutting across New England, with forests giving way to sheep pastures. Elms, however, have a tendency to warp that makes them nearly worthless as lumber. This spared the trees from the worst of the denuding. Instead, elms were often celebrated as shade givers, with particularly stately examples known by name: the Washington Elm in Cambridge, Massachusetts, for instance, under which George Washington is said to have assumed control of the Continental Army in 1775. The Deerfield, Pittsfield, Wethersfield, and Concord elms were after the New England towns where they once stood. An 1853 colored engraving of the Washington Elm in Cambridge, Massachusetts. Bettmann / Getty Images It wasn’t until the mid-19th century, though, that the elm grew into a cultural icon. Spurred by a twin push to uplift native tree species and beautify neighborhoods, the fast-growing and vast trees become a go-to for arborists. ‘They’re kind of like junkyard dogs. They can grow in really tough locations and be perfectly fine,’ said Stephanie Adams, a tree pathologist at Texas A&M University. ‘That’s why you see pictures of Main Street, USA back in those times and all the streets are just lined with American elms.’ Thousands of roadways still bear the tree’s name, and what else would Wes Craven call his 80’s slasher classic but A Nightmare on Elm Street. ‘The American elm is a symbol for American history,’ said Doug Still, an arborist and host of the podcast ‘This Old Tree.’ ‘Until, of course, Dutch elm disease wiped them out.’ The aptly abbreviated DED kills with incredible efficiency. While it likely originated in Asia, Ophiostoma ulmi was first observed in northern Europe around 1910 and Dutch scientists officially described it in 1922. The fungus that causes it soon arrived in North America, reportedly on logs imported to make veneer, and native elm bark beetles carried it on their backs as they burrowed into their hosts. The afflicted tree mounts an aggressive immune response, trying to stop the invader by deploying balloon-like plugs called tyloses that prevent transmission through the xylem, which shuttles water and nutrients from its roots to its leaves. These arteries eventually clog, and the tree essentially starves. Death can come in as little as a year. Rings are pictured in the trunk of an elm tree in Boston in 2017. Planted in the 1880s, the tree was taken down after succumbing to Dutch elm disease. David L. Ryan / The Boston Globe via Getty Images The impact on the American landscape was immediate. Trees suspected of having the disease were quickly felled to curb the plague, and, by 1935, President Franklin Delano Roosevelt had allotted $2.5 million to the effort. Culling intensified, but instead of stemming DED it may have hastened its expansion. ‘The only tool we had in our toolbox at the time was a chainsaw, and when that’s the case, everything looks like a removal,’ said Adams, explaining that, once introduced, the disease can move from one elm to another through their interconnected roots. ‘We didn’t know that removing before severing the root grafts actually exacerbated and sped up the spread.’ The 1940s brought more setbacks. America’s entry into World War II diverted attention and resources away from the elm war. Then a far more aggressive strain — Ophiostoma novo-ulmi — arrived, turning the epidemic into what one researcher, in 2017, deemed ‘arguably the most significant event in the history of urban forestry.’ This potent variant raced through the country, killing as many as 100 million trees. Though the percentage of elms lost is murky, the impact is unmistakable. Trees came down by the thousands in cities and towns nationwide. New Haven, Connecticut, once known as ‘Elm City,’ was almost entirely stripped of its namesake. The population on the University of Illinois campus tumbled from 1,850 to 92 in a little over a decade. By the 1970s, Minneapolis was taking down more than 20,000 of its roughly 400,000 elms each year, estimated Ryan Murphy, who leads the elm selection program at the University of Minnesota. A mere 35,000 remain in the city, and statewide the devastation is even worse, with the plague claiming 95 percent of the elm population. ‘In some communities in Minnesota there are just a few American elm left in the entire city,’ he said. ‘And the disease is still killing trees.’ The easiest way to find the plot of dying elms in Benson, Vermont is to put ‘Preserving God’s Creation Taxidermy’ into a GPS, and cross the street when you get there. The business is in some ways emblematic of what scientists are doing in the field below — ensuring that people can continue enjoying a species. And like taxidermy, it requires that individuals die. ‘I feel like we should warn them and apologize to them because we’re torturing them,’ said Leila Wilson, a research ecologist with the U.S. Forest Service, as she set out to start injecting another young elm. She cringes each time, knowing the consequences. ‘I don’t like that part. But they’re serving the greater good.’ In an era of high-tech fixes, Wilson, Goodwin, and their colleagues are doing little more with their elms than Gregor Mendel did with his peas: crossbreeding them. The idea isn’t new; such efforts began almost as soon as scientists learned of the disease, but no one has had much success. Between 1937 and 1965, scientists at Cornell University and the Boyce Thompson Institute grew, infected, and tested 21,000 seedlings. Only 16 survived, and many of those couldn’t pass along their genetic resistance. None made it to nurseries for distribution. That failure, among others, dampened the appetite to fund such costly, long-term research. ‘So many false hopes have been raised that there is apathy in some quarters about the outcome of our battle against this disease,’ the author of a 1975 scientific paper on the subject wrote. But, he added, ‘surely it is worth the trouble.’ ‘Trouble’ implies inconvenience and feels insufficient for the toils of restoring elms. By one estimate, only about 1 in 100,000 elms are truly tolerant to DED rather than simply lucky. But just what makes those survivor trees special remains a bit of a puzzle. Unlike the American chestnut, which was similarly ravaged by a blight, there isn’t a clear genetic marker that points to exactly what allows some elms to stave off DED more effectively than others. That makes gene editing moot and breeding the only option. Read Next The American chestnut tree is coming back. Who is it for? Maya L. Kapoor After earning his doctorate in forest genetics and plant breeding in 1969, Alden ‘Denny’ Townsend found a job at the U.S. National Arboretum’s Agricultural Research Service in Ohio. The young scientist’s work spanned a range of species and projects, including an American elm program that had lain mostly dormant for years. The assignment came as DED rampaged, and pessimism about the species was nearly as pervasive. ‘American elms were dying everywhere,’ said Townsend. ‘I thought there was hope.’ Townsend, though, inherited something of a mess. His predecessors had, fortunately, planted around 70,000 American elms at the Ohio research station that had grown to 40 or 50 feet and were available for testing. But with no proper accounting of where the trees came from, Townsend started infecting them en masse to see what would happen. Slowly, he identified tolerant elms, then cloned or bred them to generate versions with even greater resistance. After more than two decades, he eventually ended up with one variant — dubbed ‘Valley Forge,’ after George Washington’s Revolutionary War encampment — that was fit enough to send to nurseries. He identified another survivor along a road in Ohio that also proved exceptional and the arboretum eventually released it too, as New Harmony. A conservation information manager for The Nature Conservancy injects a young elm with Dutch elm disease on May 19, 2026. Jessica Rinaldi/The Boston Globe via Getty Images Since those breeds went on sale in the late 1990s, others have joined the fray. The Jefferson elm, for instance, is essentially a copy of a tree that grows on the National Mall in Washington, D.C., which boasts one of the largest remaining stands of mature American elms in the country. But there are still only a handful of cultivars available, and they have quirks. Some, for instance, have weaker crotches and snap more easily during storms. ‘They are probably better suited in parks or country clubs or where there’s lots of land,’ said Townsend. ‘If these trees do get Dutch elm disease, they’re gonna be a real hazard.’ They have another drawback too: limited genetics. There simply aren’t enough reliably tolerant strains to provide the genetic diversity needed for the widespread floodplain repopulation that Goodwin envisions. ‘It’d be like starting a population over again with six individuals,’ he said. But Townsend said previous efforts like his should be considered building blocks rather than failures. ‘Mistakes were made,’ he acknowledged with a chuckle. But he’s optimistic that the funding and scientific rigor being applied to the problem this time around will drastically improve the odds. ‘I’m glad to hear the Forest Service is continuing to work on it,’ he said. ‘Diversity is the key.’ Christian Marks started working at The Nature Conservancy in 2007 as an ecologist studying floodplains along the Connecticut River. He knew the dwindling ecosystems act as vital sponges when the water runs high, absorbing the torrent and preventing inundation downstream. The more he learned, the more he realized the peril these New England bulwarks were in. Because they rely on just a handful of species to function, the loss of even one could be devastating — and most of them are faltering. Like Townsend, Marks thought elms stood the best chance of recovery, as long as their tolerance could be boosted. While he said the roughly 90 percent survival rate often seen among cultivars might look impressive, floodplain elms should ideally live for well over a century, during which they will probably be exposed to the DED pathogen repeatedly. ‘You have to be able to survive many times,’ said Marks. That requires trees that survive closer to 97 out of 100 times, a standard that could mean the difference between a tree living 50 years or 150 years. ‘It’s a much more rigorous test,’ Marks said. An old-growth elm trees that survived Dutch Elm Disease grows in Castine, Maine, as seen in February 2022. Tristan Spinski for The Washington Post via Getty Images Ironically, earlier failures to stop DED were one reason Marks was confident he could do better. In the decades since Townsend’s work, millions more elms had died, making it far more likely that those left standing were actually DED-tolerant rather than lucky. ‘You need to have enough trees die for the ones with resistance to become apparent,’ said Marks. But, although well-versed in floodplain elms, he had no experience breeding them and reached out to Jim Slavicek, a research biologist at the U.S. Forest Service’s Northern Research Station in Ohio. The latest federal elm project had started in 2003 and Slavicek had helped set up a handful of test sites across the Midwest. The two scientists went about trying to establish one in New England too. The first thing they needed was more survivor trees, and Marks knew where to find them. Starting around 2010, he went around New England, clipping samples and sending them to Slavicek. One of the first he collected was the Rainbow Beach elm in Northampton, Massachusetts, which is over 3 feet in diameter and, he recalled, ‘magnificent.’ Eventually they amassed enough cuttings to raise 53 elms, and the Forest Service began crossbreeding them. By 2018, their offspring were rising from soil at test sites in Ohio and Vermont. Within a decade the trees stood about 8 feet tall, then 12, and soon they were ready for testing. Although Marks recently left The Nature Conservancy, he remains invested in the results. ‘This is the playoffs,’ he said. ‘What you’ve been preparing for.’ The Benson test site is surrounded by a 10-foot wire fence intended to keep the deer from making a buffet of the elms inside. Chris Hansen and John Butnor had parked their white Dodge Ram with U.S. Forest Service logos on the doors and government plates on the bumpers right outside the gate. It was early July, and the first time they’d come since helping with the inoculation in May. ‘This guy right here is completely gone. It’s not got a living branch,’ Hansen, a researcher at the University of Vermont, said, standing beside a tree with shriveled brown leaves. Then he pointed to a perky green specimen. ‘This tree right next to it seemingly has nothing going on, which is pretty cool.’ Butnor, a plant physiologist with the Forest Service, checked the tag at the bottom. ‘Thirty-eight,’ he announced, reading the survivor elm’s parent aloud. Goodwin joined him, and the trio walked among the saplings. Each time Butnor saw a healthy-looking tree, he excitedly called out the identity of its parent. Thirty-six. Twenty-five. Three. Another 38 — suggesting it may be a particularly strong donor. ‘You hear us throw around the words resistance and tolerance, and I think most of the time we should actually be saying tolerance,’ said Hansen. ‘There’s plenty, as you’re seeing.’ An initial accounting of the plot revealed a range of responses to injection, including about 800 trees that aren’t yet showing signs of DED. ‘It’s too early to make predictions about individual trees,’ stressed Goodwin, who, along with his colleagues, will monitor the elms for another two years before deciding which of their parents are most suitable for planting in the new superseed orchard. From there it’ll take another 10 to 15 years before the new trees bear seed. So far, though, the results are promising. A land management fellow with Thee Nature Conservancy walks down a row of young elms as she works to inoculate each one with Dutch elm disease on May 19, 2026. Jessica Rinaldi / The Boston Globe via Getty Images Any campaign to make elms great again will, and should, run into limits. No one particularly wants to completely revive the species, which in some cities dominated the urban canopy. ‘One lesson we learned from Dutch elm disease devastating the urban tree canopy was not to plant a monoculture of trees,’ said Doug Still, the arborist, citing the more recent plight of emerald ash as another example of why overreliance can be a problem. Today, urban planners tend to be much more restrained, said Ryan Murphy, the elm expert in Minneapolis. ‘Diversifying your tree population is a sort of a safeguard or hedging your bets against future pests or disease coming through,’ he said. ‘We’ve learned the hard way.’ Some people ask whether the quest to save the American elm is worth decades of effort and millions of dollars in funding, especially when Asian elms are naturally much more tolerant to DED. But Hansen emphasized that such inquiries are rare, and come primarily from journalists and scientists, not the public, which is generally excited about the prospect. ‘Even people who aren’t necessarily interested in trees know that elm shape,’ he said. Goodwin sees a philosophical element to the work too. ‘There’s kind of like a moral injury of extinction,’ he said. ‘This is a way to try to repair that.’ The price of not doing this work is evident on the hills surrounding the grove, which are spotted with dead and dying elms. Many look like they’re choking on epicormic shoots. ‘They’re probably not healthy,’ said Hansen. Although no one has tested them, Dutch elm disease is likely the culprit. As he walked back toward the truck, he stopped in a patch of shade and looked up at least 50 feet into the canopy of a middle-aged elm. ‘It’s called the Benson tree,’ he said. It’s imperfect — the limbs are haphazard and, as Butnor described them, ‘a little unruly.’ But the vase-like shape is unmistakably an elm and, at somewhere between 50 and 100 years old, one that has long outlived its peers. Hansen isn’t sure if it’s a survivor or simply lucky. There’s a chance Dutch elm hasn’t reached it, though now that the field it abuts is infected, that probably won’t last. Like the younger elms, the Benson tree awaits its fate. In the meantime, it stands watch over the scientists trying so hard to save its kind. This story was originally published by Grist with the headline The deadly experiment that could save the American elm on Jul 23, 2026.