For generations, our native trees have shaped the landscape and the life within it, from the chestnuts that once fed both people and wildlife, to the elms that arched over city streets.
Today, many of those giants exist mostly in memory. Chestnut blight, Dutch elm disease, and emerald ash borer have each taken their turn, leaving gaps in forests and neighborhoods alike.
Now new threats to other keystone native trees like oaks and beeches, are joining the list. It’s easy to feel that the tide is turning against our native canopy.
But nature rarely follows a straight line path. Some species are showing resilience, some are being helped by human hands, and others are waiting for their chance to recover. The story of our beloved American native trees isn’t finished yet, although what comes next depends on what we choose to plant, protect, and let grow.
Current Status of Threatened American Native Trees
Over the past century, America’s forests have faced an unrelenting series of invasions: fungal blights, insect borers, and novel pathogens that our native trees had no natural defenses against.
The American chestnut was first to fall, wiped from the canopy by blight in the early 1900s. Dutch elm disease followed, transforming city streets once lined with graceful lines of trees into empty boulevards. Since the early 2000s, the emerald ash borer has killed hundreds of millions of ash trees across North America (USDA APHIS).
Even now, new threats are continuing to emerge. Oak wilt is spreading through the Midwest and beyond (University of Minnesota Extension), Beech leaf disease is advancing from its epicenter in Ohio to the Northeast, and invasive species like the spotted lanternfly and hemlock woolly adelgid are reshaping entire ecosystems. Combined with climate stress, habitat fragmentation, and global trade, these forces are creating an era of constant pressure on native trees.
Yet the story isn’t entirely grim. Advances in breeding, biotechnology, and biological control are showing promise. Many native trees remain resilient when given space, genetic diversity, and good stewardship. The challenge now is not only to mourn what’s been lost, but to actively shape what comes next in America’s forests and neighborhoods.
Chestnut Blight and the Future of the American Chestnut Tree (Castanea dentata)
The American chestnut once dominated eastern forests from Maine to Georgia, providing food for wildlife, livestock, and people alike. It was often described as one of the most important hardwoods in North America.
In the early 1900s, however, an introduced fungus — chestnut blight (Cryphonectria parasitica), likely arriving on imported Asian chestnut stock — spread rapidly and killed billions of trees within decades, essentially removed mature chestnuts from the canopy.
The species survives now mostly as stump sprouts that rarely mature before the blight strikes again.
Current prospects
Restoration efforts are active and multi-pronged — conventional breeding (back-crosses with blight-tolerant Chinese chestnut), finding naturally surviving individuals, biotechnology (transgenic lines showing high tolerance), and biological-control approaches are all under development.
The American Chestnut Foundation (TACF) is leading the mission.
The species is not irreversibly “lost,” but its historical ecological role — a dominant, canopy‐forming tree across millions of acres — is functionally gone for now.
Restoration is possible but slow and requires public support and careful deployment. See this USDA Forest Service article for more.
Dutch Elm Disease and the Comeback of the American Elm (Ulmus americana)
Dutch elm disease (DED), caused by the fungal pathogens Ophiostoma ulmi and Ophiostoma novo-ulmi and spread by bark beetles, reached the U.S. in the 1930s.
It quickly devastated urban and rural elm populations. Once a defining street tree of American towns, the American elm nearly disappeared as DED moved across the continent.
Current prospects
Researchers and arboreta have identified “survivor” elms and are breeding and selecting for heritable resistance, and several resistant cultivars are now available for planting. Surveys and coordinated programs are actively seeking large survivor trees to broaden the genetic base for resistance breeding.
Fortunately, research programs have identified resistant cultivars such as ‘Princeton,’ ‘Valley Forge,’ and ‘New Harmony,’ which combine the elm’s classic vase shape with improved disease tolerance.
Homeowners should avoid planting untested wild elms, which remain highly vulnerable, but can safely plant these certified DED-resistant selections available through reputable nurseries.
Even resistant trees benefit from proper spacing, pruning, and sanitation to reduce disease spread.
Emerald Ash Borer Damage and the Future of Ash Trees in America
The invasive beetle Emerald ash borer (EAB) is responsible for the death and decline of tens of millions of ash trees across the U.S. and Canada, and its spread continues widely. Link → USDA APHIS EAB page
In some forest stands, over 99% of ash trees may die in heavily infested zones.
Current prospects
Biological control (released parasitoid wasps) is being implemented and shows promise at reducing EAB populations over time, but it is not yet sufficient to instantly restore ash canopy across large forests.
Individual tree protection with systemic insecticide injections (e.g., emamectin benzoate) can protect high-value ash for several years and is a valid management tool for specimen trees and high-use public trees.
Some ash may persist via root suckers or because of resistance in small numbers; long‐term population recovery will likely be slow and uneven.
Susceptibility to EAB is also not equal among ash species, and some are showing more resistance to the pest than others. Blue ash (Fraxinus) (quadrangulata) is considered the most EAB-resistant native North American ash species.
Ash is not erased from the flora, but the EAB invasion has permanently changed forest composition in many places; homeowners with a specimen ash should consider treatment options if they wish to preserve the tree.
Emerging threats: oak wilt, beech leaf disease & more
Oak wilt
Oak wilt (caused by the fungus Bretziella fagacearum) is established in many states and can kill red and white oaks quickly. Management focuses on preventing root‐graft transmission, avoiding wound‐creating activities during high-risk periods, and fungicide injections for certain trees.
Beech leaf disease
Beech leaf disease (BLD) was first noted in Ohio around 2012 and now occurs in many northeastern/mid-Atlantic states. Symptoms include distinctive banding, leaf distortion, defoliation and tree decline; causal agents are still being studied.
Other pests/pathogens
New threats continue to emerge: Sudden oak death, hemlock woolly adelgid, spotted lanternfly, and more. These shifting pressures mean the “risk profile” for different tree species keeps changing.
Because these threats keep changing and spreading, even species that aren’t currently at crisis level may become so, which means proactive monitoring, diverse planting, and flexible stewardship are essential.
What This Means for Native Plant Gardeners and Supporters
Diversify what you plant
Plant a mix of genera and species rather than monocultures (don’t plant all ash or all one maple). Diversity buffers landscapes against a single pest or disease removing an entire canopy.
Favor locally adapted, disease-tolerant selections when available
Where breeders have developed disease-tolerant cultivars (e.g., some elms) or restoration programs offer blight‐tolerant chestnut lines under testing, choose those options — but follow local guidance and provenance recommendations.
Protect high-value trees proactively (but selectively)
If you have important ash trees you want to save, professional systemic injections are an effective short-term to medium-term tool; biological control is a longer-term supplement but not an immediate silver bullet. For oaks, follow local oak-wilt seasonal guidance (avoid pruning in high-risk windows).
Don’t move firewood or untreated wood; follow local quarantines
Many invasive pests spread via infested firewood and nursery stock. Buy firewood locally and follow state quarantines and best practices to reduce long-distance jumps.
Monitor and report unusual decline
Homeowners are part of early detection networks. If you see striped leaves on beeches, sudden canopy wilting in oaks, DED symptoms on elms, or EAB signs on ash, report to your state forest health program or extension — early detection matters for containment and mapping.
Invest in tree health and age structure
Healthy trees are more resilient: water during droughts, mulch properly, avoid root damage, and limit unnecessary pruning/wounding. Planting younger cohorts of diverse natives will help future forest structure even if large trees are lost now.
Support restoration science and community programs
Join or donate to organizations working on chestnut and elm restoration, participate in local planting events, and support biological control and monitoring efforts run by universities and agencies.
Provide wildlife habitat beyond just trees
Dead standing wood, brush piles, native understory shrubs and wildflower patches all support insects, nesting birds, and mammals. Managing a property for structural and species diversity increases ecosystem resilience even if one canopy species declines. (See our article on 5 Ways to Help Wildlife in Your Yard)
American Native trees are not all doomed, but many iconic species have been and will continue to be heavily impacted by pests and diseases; recovery depends on science plus millions of smart decisions by homeowners and cities.
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