From the Field

The Quest to Restore American Elms: Nearing the Finish Line

August 9, 2017

The Wallace Elm in Colebrook, NH, harvested in 2017. This elm is the only survivor from a row of elms that lined the street in front the Wallace Farm, owned and operated by the Wallace family since 1785. Princeton elm in foreground. Photo © Gus Goodwin / The Nature Conservancy

The quest to restore the American elm has been underway for more than half a century. Today, with help from The Nature Conservancy’s Christian Marks, success is closer than ever—which is good news for our floodplain forests, as well as our urban communities.

On a humid day in mid-June, Jessica Colby is hunched over a collection of bright green stems, each one waving a leaf or two, each one a tiny banner of hope. It’s almost noon, and the temperatures in the greenhouses at the University of Massachusetts in Amherst are climbing. Colby pushes her hair off her damp brow and, wielding a small blade, gently scrapes the outer layer from the stem she is holding, before dipping it in rooting powder and adding it to the lineup of cuttings anchored before her in a moistened block of foam. The leafy stems march in straight rows across the table, like a band of miniature soldiers fighting for a cause.

Colby and her fellow interns, Izzy Bazluke and Lisette Stone, are, in fact, the latest recruits in what has been a long battle to bring back one of America’s most iconic trees, Ulmus americana. Their fearless leader, Christian Marks, a floodplain ecologist with The Nature Conservancy’s Connecticut River Program, has spent more than a decade tackling floodplain restoration in the Northeast, with a special focus on the American elm. Along the way, he’s developed an eye for what he calls survivor trees—like the two on Elwell Island in Northampton, Massachusetts, where Colby’s stems were harvested. “It’s sort of an obsession with me now,” he says. “I’m always watching, always looking.” As he drives New England’s winding roads, Marks peers into the forests, past the shadows, looking for the elm’s distinctive vase-shaped form, rising above the canopy. These massive trees—often 100 feet tall and more than 100 years old—stand alone in the forest now, surrounded by smaller dead and dying elms, reminders of another time.

Loss of an Icon

Success! Stone holds shoot section that has effectively rooted and is ready to be potted up and continue its journey to real treedom. Photo © Lisette Stone / The Nature Conservancy

The tragedy that befell one of the country’s most magnificent trees began nearly a century ago. First described in the Netherlands in 1919, the Dutch elm fungus is carried by the European elm bark beetle, which crossed the Atlantic in 1930 in a shipment of logs purchased by an Ohio furniture maker. Before long, Dutch elm disease (Ophiostoma ulmi) was sweeping across much of the eastern United States. One after another, the giant trees were infected—and then swiftly cut down. Their famously arched silhouettes, which once soared in shady cathedrals of intertwining branches along countless community main streets, vanished, leaving behind barren stretches of pavement and neighborhoods stripped of beloved trees that had stood for generations. By the 1980s, millions of elms had been lost. The devastation continued along the region’s riverbanks, where the elm had been an anchor species in the floodplain forests, providing critical habitat for wildlife and protecting human communities from rising waters during severe storms.

Today, most of us have never stood beneath one of these iconic trees. Perhaps our grandparents remember them. Or maybe we’ve visited New York’s Central Park or the National Mall in Washington, DC, where fungicide treatments and generous endowments have helped to preserve a few remaining noble specimens. But for most of us, the giant elm is the stuff of legend, a lost wonder of the natural world. And while young elms persist along our riverbanks, almost none survive long enough to reach the canopy. The ancient tree has vanished from the forest, too.

Antique Albert Fitch Bellows hand-colored-engraving by J. Duthie. The Village Elms Sunday Morning in New England 1878.

If Marks has his way, though, the legend will live again. Elms along our riverbanks will help to save an entire ecosystem of expansive floodplain forests, and generations to come will experience once more the profound beauty of these soaring trees along our city streets. But restoring a legend, it turns out, is not for the faint of heart. The process is labor intensive and fraught with uncertainty, demanding years of strict adherence to careful scientific methods—and endless reserves of patience. Success, ultimately, requires a leap of faith, an understanding that today’s efforts are a gift to the future, to forests unseen.

Labor of Love

In the sweltering greenhouses, interns Colby and Bazluke methodically complete row after row of cuttings—about 270 by the end of the day. “We thought the whole propagation process would take about a week,” says Stone, who has overseen the painstaking effort. “But it took four.” In the end, the three interns, with help from a band of volunteers, completed 4,827 cuttings. Only 25 percent were expected to take root. But three weeks later, more than 90 percent had successfully rooted, defying expectations. “It was a great problem to have!” says Stone, who then worked nearly round the clock to get all the rooted cuttings potted. Those that survive, will eventually be transplanted into trial plots, where they will be tested for disease-resistance.

Many volunteers such as, left to right clockwise, Laura Kovarik, Crystal Leckie, Benjamin Wetherbee and Hannah Morrisey, have joined Stone in the greenhouses over several weeks to aid in the propagation of nearly 5,000 individual shoots. Photo © Lisette Stone / The Nature Conservancy

This is the secret to successful restoration, explains Marks. “We need new varieties—genetic diversity.” For more than 60 years, researchers have been scrambling to develop this diversity, searching for varieties that can withstand Dutch elm disease, including a second more virulent form of the pathogen (O. nova-ulmi). “We now have seven varieties that demonstrate good tolerance,” says Marks. Two of these, Princeton and Valley Forge, were successful enough that they are now sold in nurseries and are slowly being reintroduced into the urban landscape. “But seven varieties is not enough,” says Marks. “We need to double that number for long-term survival in the wild.”

Jim Slavicek is a research biologist at the USDA Forest Service’s lab in Delaware, Ohio, where he and his team have been working on elm restoration since 2003. “The DED fungus mutates,” says Slavicek, “which means it will eventually overcome the tolerance that exists in selections like Princeton and Valley Forge. That’s why we need to focus on the forested landscape, where the most DED-tolerant trees can naturally propagate and evolve, eventually developing mechanisms that can withstand future onslaughts of the fungus.” Urban settings, by contrast, typically feature single varieties, and the trees tend not to propagate themselves. Ultimately, restoration of naturally occurring forest elms will provide a source of disease-tolerant trees for use in urban settings, too.

No one knows the ecology of floodplain forests better than Marks, who has spent years pulling on waders and exploring the Connecticut River watershed, often tramping through the forest understory in waist-high water. At nearly every site he’s studied—more than 100 in all, elms are still taking root, but they are quickly succumbing to disease, never reaching the soaring heights of centuries past. “We realized that we have to figure out how to get this species back, if we are truly going to restore these floodplains,” says Kim Lutz, director of the Connecticut River Program. And so began a partnership. The Forest Service had the facilities, skills, and staffing to do the meticulous breeding needed to establish new varieties. The Conservancy had land where new trees could be planted. And they had Christian Marks, with his intimate knowledge of New England floodplains and the region’s great survivor trees.

Arborist Mac Swan cuts branches from an American Elm in VT to obtain flower buds. The branches with the most buds are found high in the tree where the limbs get direct sunlight, making bud harvest an exciting proposition, even when tied in. Photo © Gus Goodwin / The Nature Conservancy

“Rainbow. Podunk River. Hadley. Whale Tails. Cummingham. Goff Brook—I’ve collected from all of them,” says Marks, reeling off the names of some of the ancient elms he has stood beneath each spring, watching as arborists climb 60 or 80 feet up into the spreading limbs. The clipped branches spiral to the ground, where Marks waits to collect and label them. Of the 50 survivor elms Marks has worked with in New England, only about one in four will have elevated tolerance for the disease. His tireless mission, year after year, has been to figure out which ones might hold the promise of new hope for the American elm.

Some of the branches he collects provide the cuttings to make the clonal copies started by interns at work in the greenhouse. Others are rushed overnight to the US Forest Service research station in Ohio, for the start of the complex cross-breeding process. Here, they are recut and stored in water until the flowers open and drop their pollen onto the wax paper below. Next, USFS researchers collect the pollen and head out to the trial plots, where varieties of disease-resistant “mother” elms, including Princeton and Valley Forge, have been planted. Here, the fresh pollen from the ancient survivor “father” trees is carefully blown onto individual branches, each one encased and sealed in a plastic bag so as not to be contaminated by stray pollen from other trees. “Every father tree is crossed with at least two mothers,” says Marks. “We have more than 100 crosses at this point.”

Marks leans in to observe whether or not a particular section of the Delaware-2 disease resistant cultivar is at the precise stage for effective root propagation. Photo © Lisette Stone / The Nature Conservancy

A couple of months later, the USFS team collects the seeds produced by the latest cross and rushes them back to Marks in New England, where they are planted in tiny pots—and carefully labeled. Row after row of seedlings line the tables now at the UMass greenhouses, some no bigger than a fingernail, others nearing three feet in height—about 800 in all. With help from her team, Stone checks their progress every day, noting signs of growth invisible to the casual observer. For months, the whole batch of tiny seedlings, along with the thousands of cuttings, will be carefully tended and repotted, before they are ready for transplanting to test plots in the field. Then comes the waiting and watching.

For the next several years, at sites in Vermont, New Hampshire, Connecticut, and Massachusetts, Conservancy interns will monitor the progress of the fragile elms. This summer, Colby and Bazluke spend long days in the field hacking their way through thick vegetation to reach the saplings, battling tall grasses, giant ostrich ferns, and tangles of thistle, bindweed, and stinging nettle. They measure basal diameter and height. They look for tags, making sure each tree is labeled. They spray deer repellent and check to be sure every trunk is wrapped for protection from rodents. They slash away at any competing weeds. And they keep an eye out for yellow and wilting leaves—signs of DED.

AmeriCorps member Karla Noboa (TNC VT) carries an armload of elms from the staging area to the planting fields in northern Vermont. Photo © Gus Goodwin / The Nature Conservancy

“It’s pretty wild to see all these little trees planted out there,” says Gus Goodwin, conservation coordinator for The Nature Conservancy’s Vermont chapter. “And to realize how long it will be before we’ll have any definitive answers about survival rates. But it’s a great feeling to be part of this process.” Goodwin, who is also a woodworker with an appreciation for the unique characteristics of elm wood, adapted an existing app that has dramatically improved the quality and efficiency of the field work for Marks and his team. “Essentially, it allows elm techs to use a high-accuracy GPS to precisely map where the trees are planted,” he says, “which means less time spent searching for hidden saplings!” The app also makes it easy to enter all the growth, health, and vigor data out in the field, and then synch it with the database back at the lab for speedy editing—a quantum leap from the laborious task of re-entering data from hand-recorded sheets, notes Goodwin. “And then double- and triple-checking every entry for accuracy.”

When the tiny elms reach 1 inch in diameter, the injections begin—every single sapling gets a shot of the two strains of DED. “That is the moment of truth,” says Marks. “We can tell in a couple of weeks whether they will be disease resistant. Most are dead by the end of the summer.” Those that survive—perhaps a third—will continue to grow and put down roots, pioneers in establishing a new population of wild elms.

Evidence of the elm bark beetle, carrier of the Dutch elm fungus that felled millions of American elms. Adults lay their s its eggs inside the bark. Larvae feed on the inner bark, creating a network of galleries. Photo ©Lisette Stone / The Nature Conservancy

Urgent Mission

Restoring a lost species requires a certain kind of humility and tenacity. The work is laborious. The failure rate is high. The timeline is long. But Christian Marks is not easily daunted. He has a vision of what’s possible—and he loves these trees. “I’m just lending a helping hand early in the process,” he explains, describing what he likes to call his dating service for elm trees. “Eventually, we will walk away, and the evolution of resistance by natural selection will take over.”

But first, he explains, urgency in his voice, we need to establish enough disease-tolerant trees in the same place so that they can breed among one another. The recent outbreak of a new invasive pest, the emerald ash borer, which is attacking another critical floodplain species, makes the restoration and replanting of elms along rivers in the Northeast more urgent than ever. “The good news,” says Marks, “is that we have several new varieties in the pipeline that look promising. We are nearing the finish line.”

Christian Marks shows reporter Pat Bradley from WAMC how to identify an American Elm. This tree, nicknamed the “Ghost Barn Elm” by the locals, was sampled in 2017. It is located in the Town of Keene, Adirondacks, NY. Photo © Gus Goodwin / The Nature Conservancy

A recent grant from the Manton Foundation is helping to speed the restoration process along, including the flurry of propagating work in the greenhouse this summer. “Thanks to their generosity, we are in the midst of a five-year effort to see if we can double the number of disease-resistant cultivars,” says Lutz.

Progress can’t come soon enough. As the threat of climate change continues to loom, more and more people are beginning to understand why floodplains are so important, why we need these giant protective sponges along our riverbanks to buffer human communities from rising waters. Floodplain forests also filter sediment and excess nutrients to protect water quality, and they provide habitat for wildlife and recreation for people. Urban areas, too, are poised to benefit from the return of the elm, as cities seek green solutions to climate change. Studies have shown, for example, that a single large American elm, located on the southern side of a home, can intercept 2,384 gallons of storm water, conserve 107 kWh of energy, and sequester 518 pounds of CO2 annually.

“No matter where I go,” says Mark Smith, deputy director for The Nature Conservancy’s North America Water program, “the reality of increased floods and flooding damage is front and center.” The issue unites people, he notes, cutting across every geographical boundary and every party line. From the hills of California to the fields of Iowa to the coast of Louisiana to the banks of the Connecticut River in New England, communities everywhere are looking for solutions. “One of Christian’s great contributions to this effort,” says Smith, “has been his deep knowledge of floodplains and their dynamics and what’s needed to bring them back. And, of course, his commitment to the elm.”

Elm crosses awaiting planting in Vermont’s Northeast Kingdom. Photo © Gus Goodwin / The Nature Conservancy

Thanks to the help of dedicated interns and volunteers, Marks has planted elms at more than 30 sites in the Connecticut River watershed—3,300 seedlings from crosses at the Conservancy’s field trial plots in Vermont and more than 1,000 cuttings from clonal copies of the seven disease-resistant varieties. If some of this year’s 5,000 new cuttings and crosses are successful, more varieties will be joining the original seven. Enthusiasm among volunteers is high. “There’s something about planting a tree,” says Marks. “It’s meaningful to people. It creates a tangible legacy.”

Megg Carter, of the Northwoods Stewardship Center, plants an elm on a perfect spring day in northern Vermont. She’s smiling because the day before she was planting in 3 inches of snow! Photo © Gus Goodwin / The Nature Conservancy

Some of the restoration sites, like the Conservancy’s Maidstone Bends Preserve on the Upper Connecticut River in Vermont, have been successful, boasting elms that now stand more than 20 feet tall. Other sites have struggled. One was destroyed by fire. At another, dozens of young saplings snapped in two, when rising waters froze during a winter flood. But Marks perseveres.

Several new restoration projects are about to get underway, including two in New Hampshire—one along the Ashuelot River in Swanzey and another along the Connecticut River in Colebrook. In Massachusetts, after five years of collaboration with multiple partners, the Conservancy recently helped protect more than 370 acres of rare floodplain habitat just minutes from the city of Springfield. “The scope of this project is unprecedented,” says Marks, noting that, once the Conservancy’s restoration work on the parcel is complete—roughly 223 acres—the Fannie Stebbins Memorial Wildlife Refuge will be the largest expanse of natural floodplain in the Connecticut River watershed.

The restoration effort on the Stebbins land will feature the planting of thousands of trees, including disease-tolerant elms. With each sapling planted, hope will take root once again. Hope for a future where the American elm once again rises high above the forest canopy along our riverbanks. A future where children once again look up from the sidewalk and marvel at the graceful silhouette of a giant elm, shading the street below with its sheltering branches—its presence a quiet testament to the years of dedication and commitment that powered the quest to restore a beloved tree to the American landscape.

Historical photo of Main Street in Calais, ME. Photo © St. Croix Historical Society

Suki Casanave is a writer for the philanthropy teams in Massachusetts and New Hampshire.

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    1. Gus Goodwin of the TNC Vermont Field Office developed a workflow in Collector for ArcGIS for monitoring and mapping tree plantings. For more information on the seedling monitoring App please contact Gus at gustave.goodwin@TNC.ORG. The USDA Forest Service created a website for submitting the locations of American elms over 3 feet diameter that were likely exposed to Dutch-elm-disease repeatedly yet survived.

  1. I have wept over the loss of three giant elms. Thanks for the life ring. The value to human spirit cannot be measured. Is there a champion out there for the chestnuts and ash. Please.

  2. Is it possible to graft a piece of a tree, that has shown resistance to the beetle, with a branch of the elm and have better results?

    1. Yes, it is possible to graft elms. Indeed grafting and other vegetative propagation techniques are the only way to guarantee that the elm seedling will have the same level of resistance as the parent tree.

    1. Seed generated from controlled crosses is in short supply and dedicated to use by researchers in the breeding program.

  3. Please publish information on how to identify elm trees and also Chestnut trees. Also, please publish a contact that the general public can inform this project if they have any of these old trees growing on their property. There is a very tall tree growing on the side of a ravine among a stand of honey locusts that I cannot identify. It is in a preserve area next to my property. It turns out to be elm or chestnut, I would like to be able to alert the people who are trying to restore these trees to our world.

    Thank you
    Sandra Utrata

    1. Take some pictures of the leaves close up, bark, and a view at a distance. I am sure it can be identified.

  4. This is wonderful news, THANK YOU all for your efforts in such an important task. These kinds of projects are never given enough media coverage. I never knew that The American Elm tree was endangered and or in trouble or practically gone. It seems our focus is not flowing in the correct direction for our planet. How sad that people don’t know this. Once again Thank You.

  5. I have what I believe to be a massive Winged Elm at my cabin in West Tennessee. Would that be of help to you.

    1. At the moment, research by our team is exclusively focused on American elm (U. americana) because that is the most widespread and common of the native North American elm species in both cities and in the wild. Unfortunately, we do not have the resources to include the other native elms species such as winged elm in the research at this time. Winged elm is most easily recognized by the very broad, thin pair of corky wings that form along the branchlets after a couple of years. Please see answer above for identifying and reporting exceptionally large surviving American elms.

  6. I purchased a property in Paterson NJ Eastside historic district in 2014 that needed extensive tree work due to property neglect. The arborist pointed out an elm bark to bark with a 10″ diameter Ailanthus. The elm is actually two gradually merging. I don’t know the age but the house was built in 1939 or 40 and this Siamese pair were not part of the intended landscaping. The Ailanthus was a well-formed specimen. The elm twin was a bit distorted to one side by the invader but I chose to have the Ailanthus removed. I had lived in NYC for 27 years and had taken the citizen pruner course so I was well aware of DED and knew the likelihood this elm would not avoid succumbing to the disease. I also knew the Ailanthus was going to take revenge in years of persistent sucker shoots sprouting everywhere. But I thought I’d rather give the elm a chance. It seems to flourish and is putting out new growth on the side where it was bullied by the blessed “Tree of Heaven”. I am no expert but see no signs of leaf yellowing. Perhaps it already has DED and I just don’t see it. Right now the biggest threat is from an ancient oriental bittersweet on the neighbor’s property they have allowed to overwhelm an evergreen. It is sending shoots over into the upper reaches of the elm and I’ll have to have the arborist back to get up there and stop it as it is too far up to reach from the ground. I don’t know if this is actually an American Elm or another sort. It is growing on the line of an old decrepit chain link fence and so is obviously a volunteer. I’d guess it to be 30-40 years old based on what long term neighbors tell me about when the previous owners gave up on the gardens of what once was a well-landscaped home. I wonder if there is interest in this tree as a survivor–at least for now–that has received no special treatment or care. Perhaps it’s not an American Elm, but maybe it is. It is taller than the house which is two stories and seems quite vigorous.

  7. My son lives in Oak Park, IL. and I believe there is an American Elm in his backyard. The tree is huge, close to four foot through and about 100 ft tall. He also has a lot of saplings growing in his yard. I suggested that he contact someone in Oak Park about the tree and see if someone would like to possibly get some starter saplings. I will continue to have him investigate more, and I’m thinking about digging up a sapling for my yard, down in Bloomington, IL.

  8. Maybe because I am descended from pagan Irish who worshiped oaks from time immemorial, I have always been a passionate lover of trees, those giant flowers that provided our ancestors with warmth, shelter, food, clothing, pure water, and spiritual inspiration. I’m delighted to learn that the struggle to save the elm from extinction is showing promise. Here in eastern Maine, numerous specimen elms of great size endure, preserved from disease by physical isolation. Planting trees you will never live to see mature is a humane act that keeps faith with people of the future; it is a spiritual act!

  9. Are there any elm restoration projects taking place in PA – along the Delaware River perhaps? I’d like to be part of it.

    1. Hi Alice,
      DED resistant elm cultivars like Princeton and Valley Forge are available in the eastern PA area from various nursery sources. I’ve planted over 50 elms in my Philadelphia neighborhood of South of South. American Elms are a great urban street tree, guess that’s why they’ve been called, The Great American Street Tree by arborists. Elms grow fast and in a vase shape so they get out of harms way at the street level-delivery box trucks pulling to the curb breaking off branches are one of the most common assaults on street trees. An american elm planted in front of my house on Christian St. 15 yrs ago now shades a large part of the street (but allows some sun to filter thru) and is approaching 50 ft in height.
      Larry Shaeffer

    2. The Nature Conservancy is planning to include planting of American elm selections with high disease tolerance as part of a floodplain reforestation project on the Neversink River ( ), a Delaware River tributary in NY.

      If you would like to plant American elms in your state, you could work with a local nursery to procure some of the commercially available American elm selections that have a high level of disease tolerance. These selections include the following: “Valley Forge”, “Princeton”, “New Harmony”, “Prairie Expedition”, “Saint Croix”. Your partner nursery may need to order these elm selections from a relevant wholesaler a year in advance. Wholesale nurseries supplying these selections in the USA include the following: Bailey Nurseries, J.Frank Schmidt & Son, JLPN Liners, and Sester Farms.

  10. I know of a few in upstate n.y. one blew down a few years back but still a couple of at least 24 in. diameter around if your interested

  11. I was born in Eastern Iowa and my hometown was Lone Tree, Iowa. It was so named for an American Elm tree that stood on a hill in the midst of the tall grass prairie. The indigenous people and European settlers used it for a landmark. There were even settlers and infants that were buried surrounding it. They estimated the tree to be almost 200 years old. Sadly, in the 1970’s the tree succumbed to DED. I now live 40 miles West of Chicago not far from theMorton Aboretum which has developed a cultivar,Ulmus Morton Plainsman. It is a very nice tree and it is resistant to DED, but it serves as a street tree and shade tree, but still is lacking the glory of the American Elm of my childhood. Thank you for all you do??

  12. Interesting and very cool article! One question. The article says a single elm can “sequester 518 pounds of CO2 annually”. Are you sure on that statistic? Leaves that grow and then rot do not represent sequestered carbon. And 500 pounds seems like a LOT of trunk growth for a tree in one year.

  13. There is a healthy American Elm at Longwood Gardens in Kennett Square, PA. In case your team doesn’t know about it. Contact the Horticulture Department for information. There is a team of arborists on the staff who care for all the trees on the property.

  14. I wish them the best of luck. We lost some young “Liberty” elms in the Elm City this year. On Marlboro Street, West Street.

  15. I read this article with great interest. I grew up on a farm in Minnesota. The elms on the property were magnificent and I cried as I watched them die off. I wanted to let you know that I have seen a fine specimen of an elm along route 31 in Michigan between Interlochen and Traverse city. I even have a photo of it somewhere. it is tall and magnificent like the trees from my childhood home. Each time I pass it I make note of its continuing good health.

  16. I so miss the elms of my youth. There were many throughout the suburbs of Chicago in which I lived and we were fascinated by the “writings” we found on the bare trees in our woods. As kids, we were not aware what those messages truly meant–the eventual loss of those numerous, beautiful trees. Though the trees do not have the majesty of a spreading elm tree, our city chose to treat its ash trees when the emerald ash borer appeared. It is a continuous battle but worth it. I applaud the work of the Nature Conservancy and wish them the very best of luck in reviving the elm.

  17. Hi, how do I get in touch with the Conservancy via email to get some of the Elm cuttings to grow in an orchard?

  18. This article is extremely self aggrandizing, when one considers the duration and depth of nationwide commitment to solving the “elm problem”. An especially glaring omission is the early work undertaken by the Morton Arboretum in suburban Chicago. The City of Chicago and its suburban communities were among the first to development Dutch Elm Disease management programs. The American Elm was a signature tree of thousands of Midwestern communities, and these communities have never recovered the beauty and shade provided by this amazing tree.

  19. Port Gamble in Western Washington state has a number of OLD American Elms that were planted there in the late 1800’s. Perhaps Suki Casanave or someone else could pass this info on to relevant parties

    1. Dutch-elm-disease reached western states more recently than other parts of North America, and it is possible that it has not spread to Port Gamble yet. If there has been a wave of elms dying in Port Gamble in the past, then the survivors of that die-off would potentially be of interest to researchers. Please see answer above on reporting survivor elms.

    2. Seattle still has many large old American elms. (An earlier post mentioned elms still extant in historic Port Gamble, Washington, a pioneer town established by Maine logging interests). I wanted [to plant] one. Prior to moving to my current house in 1985, I picked up a lone seed, one of tens of thousands which littered a certain street on Capitol Hill, and germinated it. It is now a very large, beautiful tree. I realize that DED has since arrived in the area, some years ago, if fact. My tree, somewhat isolated from other elms, is still healthy. I only regret that the thousands of seeds it disperses yearly are produced for naught. It gives me much pleasure.

  20. When we bought our home in Evanston, IL 44 years ago, our block was lined with large elms. We watched sadly as over the years those trees fell victim to Dutch Elm disease. There are two left on our block. One is in front of our house. It is a magnificent tree that certainly seems to be holding its own. Fortunately, our city inoculates the elms that remain in our city. In answer to the question about chestnuts, we met a man from Texas, I believe, several years ago who was very active in the effort to save the American chestnut.

  21. I have a very large seemingly very health elm tree that was large when we moved out here in 1989. It is really big now, and seedlings show up EVERYWHERE every spring! If anyone has any interest in pics, seedlings or a trip to Oklahoma you’d be welcome. It is my favorite tree and I have planted several of it’s seedlings. If I can help I would love to, this is a wonderful thing you are doing.

  22. This is very important. I try to go to the local cemetery and preserve some seed to see if they will grow and bring back the need growth to replant. Nothing has grown yet. But there is a tee in there that Daniel Webster himself climb, and not many people can claim that. This is a very important program to bring back rare and native plants. It is a beautiful thing you are doing. Thank you. Oh, and in the middle of the city of Manchester I found a native pear tree that no one know about. It is diseased. I am trying to save as many seeds as I can. It is sad.
    Thank you again. Kathy Lee

  23. I remember as a kid, Elm St., in my home town of Plaistow Nh, going from a half mile of elm canopies to “Utility Pole St.”. They are all gone. A slab of the I do believe was the largest elm tree in the state sits preserved in the town hall vestibule. Reading of this effort to bring them back, though I will never see the full grown grandeur, is truly a heart warming read. I wish them every success.

  24. Congratulations to this project!
    Is the American beech getting any attention, I wonder?

    1. The American beech is getting some attention (for example see ), but less than the American chestnut or the American elm. One reason for the lower level of attention is that beech trees with resistance to bark disease are much more common than native elms or chestnuts with elevated disease tolerance.

  25. Great job folks. I hope the project is looking for other survivors in the American Elm range…they exist in the upper Midwest – the UP of Michigan and northern WI. Keep up the good work!

  26. My hometown, Winnipeg, Manitoba, Canada, has the largest surviving urban elm forest in North America (an estimated 270,000 trees in total). Many of the older neighborhoods still have the green cathedral canopy arching over the streets with trees over 100 years old. They have an urban forestry program to quickly identify and remove Dutch Elm diseased trees, but this can only slow the spread and not eliminate the risk. It’s a slow war that cannot be won (here’s an overview of the city program:

    The Red River of the North (which runs through Winnipeg) has many ancient elms in the floodplain that stabilize the river bank and are hundreds of years old. It would wonderful to partner with the Winnipeg “Save the Elms” charity to identify large tree survivors that demonstrate resistance to Dutch Elm Disease and expand the diversity of this breeding program. Here’s a link to the “Save the Elms” website:

  27. I am from Saskatoon Saskatchewan, Canada. We are so lucky not to have DED yet. We have streets in our older neighbourhoods that are lined with American Elms. They form a beautiful canopy over the streets with their arching limbs touching in cathedral-like architecture. We cherish these trees and have a diligent urban forest and Dutch Elm Disease program that is in constant watch, monitoring for any signs of the disease.

  28. Thank you all for your interest in reporting elms. Here is how to report an exceptionally large surviving elm to researchers:
    1. Check that the tree is indeed the native American elm species. Breaking off a piece of bark and looking at its cross-section is a reliable year-round way to identify Ulmus americana. U. americana bark is unique in that it has alternating cream colored and brown layers. In old elms the cream colored layers are often very thin.
    2. Measure or estimate the trunk diameter or circumference at breast height. To qualify as exceptionally large, the elm should ideally be over 3 feet (90 cm) in diameter. Please do not report elms smaller than 2 feet diameter because elms are fast growing trees that can frequently reach around 2 feet diameter before they succumb to the disease.
    3. Talk to the owner of the elm to find out if the tree has been treated with fungicide injections in the past. Please do not report elms that have been treated in the past because researchers want to find elms that are able to survive unaided by treatments.
    4. The most promising elms have been exposed to Dutch-elm-disease multiple times, yet survived. A sign of likely past exposure is that there are dead elms nearby. Make note if there are dead and/or smaller live elms within 300 feet (90 m) of the tree being reported.
    5. Enter the information on the following USDA Forest Service Northern Research Station webpage:

  29. There is a large American Elm in front of the house I grew up in in New City, Rockland County, New York. If you are interested I would be pleased to reach out to the current owners to gage their interest in providing cuttings,
    Great work, Tim Delorm, RLA

    1. Thank you for your interest! Please see the comment from Christian O. Marks on how to report a large survivor tree.

  30. Elms were popular trees in the Chicago area in the 1950s. Then Dutch Elm killed them off, or storms took down weakened trees. In the fall, their serrated leaves looked golden before they spun to the ground. These magnificent trees were quite tall so they offered both excellent shade to humans and nesting branches for birds. Thanks for bringing them back.

  31. I grew up in Boone, Iowa and in the 40’s and 50’s we had beautiful elm trees everywhere along our streets. Des Moines and many towns had the same. Then Dutch Elm disease arrived and killed most of the trees. It was devastating to the look and feel of my lovely home town. 40 years later, Boone was building a new middle school and needed many trees for the parking lot and elsewhere. They planned to plant Linden trees and I offered o buy 25 Jefferson Elms. They along with 25 Linden trees were planted 20 years ago. I was back there this year and all the Linden trees were gone, got some disease, and the Elm trees were thriving. I took pictures of the Elm trees and encourage towns in Iowa and elsewhere to plant these majestic trees. We own 41 acres in Virgin nia and are planting Elms around the property.

  32. Such a beautiful graceful tree is the elm. There are several along the roadsides in my little town of Union, Maine. I love to pick out there silhouette on the horizon on my way home.
    This is a wonderful project that has been undertaken with hope for the future of the elm.
    Thank you for preserving there beauty and utility for future generations.

  33. My beloved Nana’s home on 100 Elm Street, Mechanic Falls, had a most wondrous elm tree in front (the entire street was lined with them) which provided lovely shade and majesty. I remember well as a child, the Dutch Elm Disease and the eventual loss of every single elm on the street. These beautiful sentinels disappeared during my childhood and I recall a palpable sadness, even as a young person. I applaud the efforts by Marks et. al., to bring back this icon.

  34. I have a surviror elm on my property, unscathed while others are all dead. So nice to see.

    1. Thank you Christopher! If you haven’t reported your tree yet, please see the comment from Christian O. Marks on how to report a large survivor tree.

  35. I am so very excited to read this report. When I moved into my house here in Byron Center, Michigan 24 years ago, the elm trees in the far back area of the yard that bordered a wetland were tall and beautiful. Gradually I realized they were dying but I didn’t know what the cause was. Now they are completely dead, some having fallen down in the severe wind storms. Small ones have shown up but I’m paying attention to how they grow. But I will keep looking for your reports on the disease resistant varieties so, hopefully, one day there will be those elms in my backyard again. A grateful thank you to Chris Marks and all those who are working hard on the effort for the elm tree.

  36. What an incredible article. If we lived out east, we would love to work in your project.
    We have a wonderful old elm that is suffering from drought and storm breakage. How can we help preserve it? We are high above the banks of the Mississippi River in Grafton Illinois .

    1. If you have a special elm tree that you would like to preserve, you could have a certified arborist in your area take a look to figure out what might be done about the storm breakage. Many arborists also offer fungicide injection treatments that can protect the elm against Dutch-elm-disease. These treatments although costly are effective if done every 2 to 3 years.

  37. The house where I grew up had a semicircle of elms around it; all died from Dutch elm disease. It’s wonderful to imagine that future generations will be able to enjoy the beauty and wonderful, cooling shade these trees can provide.

  38. This was fascinating. I grew up in Madison Wisconsin which was beautiful with the arching else over many of its streets. It was awful when Dutch Elm Disease killed them. Keep up the good work. I was just amazed at the work and the number of cuttings/seedling that you have worked with. Elms are beautiful trees and I hope that you can bring them back.

  39. I have a friend who lives in Catonsville, MD. Her street tree is a huge old Elm that does not have disease. I wonder if it has ever been selected for sampling?

    1. Thanks Linda! If your friend hasn’t reported the tree yet, please see the comment from Christian O. Marks on how to report a large survivor tree.

  40. That’s great! The work you do is a real contribution in combating climate change but maybe even more, is adding beauty to our world. ??
    I know this work is being done for American chestnuts, has that gone anywhere? Diane F

  41. So glad to see this happening! We had five elms in our yard when Dutch Elm Disease hit. It was a very personal tragedy for us. Thanks for this article.

  42. If you are looking for wild elms, I believe I have at least two on my property in Maine. If you would like to check them out, please contact me. I would love to have them both survive into old age; they’re approximately 30 years old and I have watched them grow from knee-high saplings to taller than the house.

    1. Hi Karen, Please see the comment from Christian O. Marks on how to report a large survivor tree. Thank you!

  43. Thank you for this loving restoration project. The streets of the neighborhood in Chicago I grew up in
    were lined with mature elm trees. Our 3rd floor apartment was just below the tops of these magnificent
    trees which provided shade and beauty. Our apartment had a bank of windows in the living room
    and back reading room to enjoy communing with them. Later, as an adult, learning that they had suffered fatal disease and were gone was heartbreaking. I am so grateful for your working so hard to bring them back. I’m not surprised to learn they are so important to combat the devastating effects of climate change.

  44. Our house was built in the 50’s under the protection of a wonderful, big protective elm tree! It, too, was infected with Dutch Elm Disease, and had to be taken down. Sad day, and no other tree has been able to come close to replacing it! SO happy to hear of this effort, and thanks to all for the hard work! Wishing great success in this endeavor, so more people can feel the protection of a huge elm near their home.

  45. Fascinating stuff. Do you have contacts with researchers / elm tree propagators in Europe? I live in the Netherlands, and these days many of the trees lining the streets in my village are elms again. Not the American kind, but still, interchange of information might be useful.
    Also nice to read about the app. We use ArcGIS online for our work with the Dutch Forestry Commission too.

  46. We have a large old elm tree and some smaller ones growing on our property in Lovell, ME –apparently resistant to Dutch Elm disease and multiplying on their own. It’s great that you are working on bringing these back for all to enjoy.

  47. Ty for all your effort. These beautiful elms are crying out to be restored. They do not want to become extinct.

  48. Do you need any more resistant elms to collect from? We appear to have one in our woods.

    1. Thank you for your interest! Please see the comment from Christian O. Marks on how to report a large survivor tree.

  49. Thank you all for your unselfish efforts. Your love for our earthly home is heart-warming. I am grateful for your efforts to reinstate this valuable tree into the American landscape. Our Creator must be watching your progress with heartfelt interest, as this is the home he has given us to nurture and care for. I enjoyed reading this article and learning about this wonderful tree.

  50. We would love to plant some elms on our 20+ acres. How can we do that?

  51. I know one or two “second growth” elms that have apparently overcome naturally the dutch elm disease. They are located in Sharon, Vermont. If anyone is interested in these trees, I’d be glad to meet with them this summer.

    1. Thanks George! Please see the comment from Christian O. Marks on how to report a large survivor tree.

  52. I have been a lover of trees since childhood. The loss of the beautiful Chestnut, American Elm and now the battle of the White Ash with emerald ash borer have been painful to me. I have seen a very few small Chestnuts, and used some chestnut lumber in cabinet making but only saw dead trees and logs in my middle age. we used dead tees for fence posts on the farm because the wood is very rot resistant. I’m 86 now and don’t expect to see the chestnuts come back, but its encouraging to read about the dedication of these young professionals who are basically devoting their lives to such a monumental yet noble task. Thanks and God bless you and your work.
    Warren M. Whittemore

  53. I have young elm trees growing all around my property. Unfortunately they usually sprout up in areas where I cannot leave them or are too difficult to get at to transplant them. The largest one reached a height of about 50′, but unfortunately died. I assume it developed Dutch Elm disease.

  54. My Liberty Elm succumbed to DED this summer after about five years of growth in my yard in Glastonbury, CT. I am devastated by the loss of this beautiful tree. All the neighbors commented on how fast it was growing. But, alas, all the leaves have flagged and almost every branch is affected. I only noticed the withering two weeks ago. Wow, that was a speedy death for my poor elm.
    So disease resistant trees are still very susceptible, and you may only find this out after years of enjoying the tree. If you have the money to treat the tree with fungicide every three years, you may have it live longer than I had my tree, but really, do you want to have to do that?

  55. When I lived in Wisconsin, about 15 years ago, a friend who was trained as a landscape architect said that he was surprised at how many Elm trees he saw during his visit. He flew into Chicago and drove to Oshkosh. I see the work in this article is taking place mostly in New England. I hope that different areas of the country are sharing some of their Elm stock with one another, especially if you are trying to cross breed.

  56. I live in Westchester, Illinois. Westchester had many elm trees planted by Samuel Insull in the 1920s. These trees died from Dutch Elm in the 70s and 80s. Few are left. I planted two Princeton elms in my front yard, one in about 2002 and the other about three years ago. Both are doing well. The oldest one I got from a nursery in Georgia. They sold trees to Prince Charles of England. They do not seem to be in business anymore. The other tree came from a nursery in Joplin MO.

    Westchester’s streets were lined with elms when I was a little guy and provided great shade and airconditioning. If you want cuttings or seeds from my elms, I would be happy to provide them.

    Good luck in bringing back the elm.

  57. Hello,, can this process be applied to the pine bark beetle thats killing most of our western forests?

  58. In 2007 I ordered and planted a Princeton American Elm from River Edge Farm in Georgia. For 13 years it appeared to thrive reaching a height I estimate at 25-30 feet. Last year I noticed a split between the main trunk and one of the major side branches. That side branch never leafed out last year and the foliage on the rest of the tree seemed rather weak. By late summer all the leaves had died off. In a strong wind this Spring the partially severed limb snapped off and the tree now shows no signs of life. In fact a good part of the bark has now fallen off and what I assume are insect tracks are visible on the exposed trunk and on the inside of the detached bark. I will proceed to cut the tree down later this Spring or early Summer. Would photos of the damaged/dead tree be of any use to you? Is there any species of Elm available now which might survive in my area? I live in Rochester, NY. Thanks. LTS

  59. I would love to help promote interest and support, by photographing this species, so that I can publish an interpretive note card worthy of inclusion in my line of stationery I distribute broadly. I am about to publish an image I made of an American Elm which I photographed just west of Fargo, North Dakota. I have many other such images, and a large lithographic art print of cottonwoods in Alaska. I invite you to contact my studio. I travel widely, and am about to venture across the country on such projects. All of my work is large format, 4 x 5″ film. Cordially, Myron Rosenberg, P.O. Box 101900, Anchorage, AK 99510-1900 Studio: (907) 745-1961

  60. A helpful review. I have discovered what I believe is an American elm. It is is in a natural wooded area of a residential development. It is about 12 inches diameter at the base and looks healthy. I have found no other shoots nearby. I would be willing to take a sample for evaluation if requested, and sent it to you.
    Robert W. Merriam 919-942-3363

  61. Thank you Suki Casanave for this article and thank you Christian Marks + team for spearheading this research.

    Have any surviving Elms growing further west been sampled?

    A few years ago when I was visiting relatives in Wisconsin and Minnesota I was dumbstruck to see Elms as casual parts of the landscape. At first I didn’t believe what I was seeing, and asked my relatives if these trees were indeed Elms, and was told offhandedly that indeed the trees were Elms.

    As I drove around the two states, I saw more and more living Elms, including two incredible trees on either side of a farmhouse, towering over it. If the farmhouse was ±40’ tall, then the twin trees were in excess of 100’ in height.

    As I understand it, the phenomenon of American Elms in Wisconsin and Minnesota is due to how Dutch Elm disease spread across the US: from east to west. Because Lake Michigan is oriented north-south it established an effective barrier to its spread in the states to its west.

  62. There is a huge American Elm tree on State Street near the Ralston city hall in Ralston, NE. Apparently it is resistant to the Dutch Elm disease. Chinese elms are ugly in comparison. I grew up with elm trees and remember how fast the disease did them in.
    Craig in
    Ralston, NE

  63. We have a huge old elm on the edge of our nature with weird growths about a foot across on its trunk. These appear to be places where limbs may have begun but were somehow inhibited from growing. Tiny elm leaves grow from some of them. the tree is very old as it is large enough in circumference that one can’t embrace it. If you’d like a picture of it I’ll try to get one. It might be a tree you’d want to include in your studies/project. I don’t have an increment borer or I’d determine age that way. I know there is another method (DBH?) I could try, but from its considerable girth and height I’d say several decades. Dru Clarke 7810 Hopkins Creek Rd. St. George, Ks. 66535 785-494-2419 (we have a small farm with horses and cattle)

  64. I know of one naturally resistant tree near Waterloo, Ontario, Canada. It is about 50 feet high and has many seedling around it, some of which appear to be resistant as well.

  65. Hello,
    I live in Brooklyn, Connecticut and My Oak and Hickory trees were decimated a few years ago by the Gypsy Moth scourge. I have approximately an acre of land where I had to cut down half a dozen or so trees where I would love to plant the disease resistant Elm trees. Would appreciate any input.


  67. My wife and I have a very beautiful and healthy looking Elm tree on our property in Shelburne Massachusetts. This year this Elm produced a large number of seeds. I gathered up some of the seeds and planted a few last week. As of now they have not yet come up. One interesting thing is that our living Elm had a close neighbor Elm which died about 5 years ago. Our living Elm seems so far unaffected.

    If this sounds like something of interest we would be interested in any input and even a visit if anyone wished to examine this tree.

  68. Good Morning,

    We live in Bow, New Hampshire just south of Concord and we have a very large American elm tree in our back yard and I am trying to find out what we can do to ensure it’s long life. Could someone contact me to talk about it? It’s trunk is 4 feet across near the base and it seems to be very healthy but as I was researching what type of tree it is I came across the information about the Dutch elm disease. My cell phone # is 603-244-9752 or email is fine too.


  69. I grew up with these trees and still remember them lining most city blocks. They were a stately, majestic variety that I believe our government allowed to die without attempting to ward off the infestation of the beetle that all but destroyed the species.

  70. Now that we have CRISPR, can we modify the trees to protect themselves from beetle infestation and/or suceptibility to infection?

  71. Adding to the list of possible sources of additional cuttings mentioned by other commenters, there are numerous large elms remaining in Falmouth MA along Main and Shore Streets (I do not know if there was a treatment program that kept them going, or if they are perhaps a different species that could be mistaken for the American Elm, but certainly they look like the old elms I recall from the University of Maine Mall). Feel free to contact me at associated email address if you are interested in additional info.

  72. I came across this article when looking up the street in our backyard. I believe it’s an elm tree it’s probably 2 1/2 feet in diameter I was just wondering how many trees were left from the original disease.