Elm Tree Diseases: Dutch Elm Disease and What Replaced It

Elm tree diseases are a different conversation than apple or peach tree diseases. The American elm (Ulmus americana) was the dominant urban street tree across North America until Dutch elm disease arrived in 1930 and killed millions of trees over the next 50 years. Most of the great American elms that remain are in places where the disease never reached or where aggressive injection programs kept them alive.

The modern story is more hopeful: plant breeders have produced several elm cultivars with strong resistance to Dutch elm disease. Princeton, Valley Forge, New Harmony, Lewis and Clark (Prairie Expedition), Jefferson, and several others are reliably safe choices for new plantings in regions where the disease is still active. They look like American elms because they are American elms, just bred for resistance.

This guide covers Dutch elm disease in detail because of its history and ongoing presence, plus four other elm problems: elm yellows, elm anthracnose, bacterial leaf scorch, and elm leaf beetle. If you’re planting new, the cultivar discussion at the end matters most. If you have a mature elm in your yard, treatment options are limited but real.

How to tell which disease you’re looking at

Quick visual triage. Match the most obvious symptom and jump to the section below.

• Sudden wilting and yellowing of leaves on one branch, then progressing through the crown: Dutch elm disease
• Mid-to-late summer yellowing across the canopy, drooping leaf petioles, premature leaf drop, brown discoloration under the bark: elm yellows
• Brown irregular spots on leaves in spring, sometimes with twig dieback: elm anthracnose
• Marginal leaf browning (“scorched” edges) progressing from older to younger leaves over summer, dieback over multiple years: bacterial leaf scorch (Xylella)
• Leaves skeletonized (eaten between the veins) or with round shot-holes in midsummer: elm leaf beetle

For new plantings, the practical takeaway is that modern DED-resistant cultivars are largely safe from the disease that killed the old American elms. The trees in the resistant cultivar list below are genetically Ulmus americana but with the resistance bred into them through decades of selection work.

Dutch elm disease

Dutch elm disease (DED) is the most consequential tree disease in North American history. According to The Morton Arboretum, the first introduction occurred in 1930 in Ohio, with a second larger outbreak in 1933 in New York and New Jersey. From there it spread across the continent. By the 1980s, hundreds of thousands of mature elms across the US and Canada had died.

The first wave of DED was caused by Ophiostoma ulmi. That species was later displaced by a more virulent introduction, Ophiostoma novo-ulmi, which caused a second wave of disease and remains the dominant pathogen today. The fungi are vectored primarily by European elm bark beetles (Scolytus multistriatus) and native elm bark beetles (Hylurgopinus rufipes), which carry spores on their bodies as they move from infected to healthy trees.

What it looks like

The classic symptom is sudden wilting and yellowing of leaves on one branch of an otherwise healthy-looking tree, often in late spring or early summer. Within weeks, the wilting progresses to adjacent branches. Leaves on affected branches turn yellow, brown, and drop. The disease can move through the whole crown within a single growing season on a susceptible tree, or progress over 2-3 years on a partially resistant tree.

A diagnostic test: peel back the bark on a recently wilted branch with a knife. Brown or dark streaking in the sapwood under the bark, especially in the most recent annual ring, is the signature of DED. Healthy elm sapwood is white or cream-colored.

Why it happens

The fungus spreads two ways:

1. Beetle transmission: bark beetles emerge from dead elm wood in spring, fly to feed on twig crotches of healthy trees, and introduce spores when they wound the bark.
2. Root graft transmission: elm roots from adjacent trees naturally fuse together underground. Once one tree in a row has DED, the fungus moves through the connected root system to neighboring trees within months.

This is why isolated yard elms often survive longer than street elms. A solitary elm has no nearby roots to graft with. A row of street elms shares roots and infections through them.

What to do about it

For susceptible American elms with confirmed DED, the options depend on how early the disease is caught.

• Sanitation pruning: remove the wilting branch immediately, cutting at least 10 feet below the lowest symptom into clean white sapwood. Bag and burn the prunings. This works only if the disease is caught in a single branch and the rest of the tree shows no internal streaking.
• Trunk injections with fungicides (Arbotect, propiconazole) prevent the fungus from establishing in trees that aren’t yet infected. They’re applied by certified arborists, cost $200-1,000+ per tree depending on size, and need to be repeated every 2-3 years for protection. Trunk injection is the only treatment that consistently keeps a healthy American elm alive in a DED-pressure area.
• Root graft severing: in a row of elms where one tree is infected, trench between the diseased tree and adjacent healthy trees to cut the underground root grafts. This prevents the fungus from spreading tree-to-tree underground. Trenching is expensive but effective.
• Remove and destroy confirmed infected trees promptly. The brown-streaked sapwood is the bark beetle’s egg-laying habitat, and a dying elm becomes the source of next year’s beetle population.

These interventions are professional-only work. DED treatment is not a homeowner DIY project.

How to keep it from coming back

For replanting, cultivar choice is everything. Resistant elm cultivars exist and they work.

Resistant American elm cultivars (Ulmus americana):

• Valley Forge: high resistance, classic American elm vase form, 60-70 feet at maturity
• Princeton: excellent resistance, upright spreading form, 55-65 feet, fast-growing
• New Harmony: high resistance, similar growth habit to Princeton
• Lewis and Clark (Prairie Expedition): developed in North Dakota, high resistance, cold-hardy to zone 3
• Jefferson: high resistance, narrower upright form than Princeton

Resistant hybrids and Asian species:

• Accolade (Ulmus japonica × U. wilsoniana hybrid): excellent resistance, vigorous, broader canopy
• Triumph (Accolade × Vanguard hybrid): high resistance, fast-growing
• Patriot (Liberty × Urban hybrid): high resistance, upright form
• Frontier: resistant hybrid, smaller stature 40-50 feet, reddish fall color
• Lacebark elm (Ulmus parvifolia): near-immune to DED, exfoliating bark, smaller stature
• Siberian elm (Ulmus pumila): highly resistant but weak-wooded and considered invasive in some areas; not recommended

For more on choosing the right elm species for your yard, our types of trees guide includes notes on elm cultivar selection by region.

Elm yellows

Elm yellows is the second major elm disease, caused by an unnamed phytoplasma (sometimes called Candidatus Phytoplasma ulmi). It’s less common than DED but kills trees just as completely.

What it looks like

The University of Illinois Extension describes the classic pattern: symptoms appear in mid-to-late summer with chlorosis (yellowing) of foliage, drooping leaf petioles even when the leaves are still turgid, and premature leaf drop. Unlike DED, which often shows on one branch first, elm yellows tends to affect the whole crown more uniformly within a few weeks.

A diagnostic test: peel back the bark on the lower trunk (not the upper branches). Elm yellows produces a butterscotch-brown discoloration of the inner bark (phloem) that’s easiest to see at the trunk level. Some infected trees produce a wintergreen smell when the inner bark is exposed, though not all do.

Why it happens

The phytoplasma is spread by the white-banded elm leafhopper (Scaphoideus luteolus) and possibly other leafhoppers and spittlebugs. The pathogen overwinters in the roots of American elm. When new growth starts in spring, insect vectors pick up the phytoplasma feeding on young shoots of infected trees and transmit it during feeding on healthy trees.

Elm yellows also moves through root grafts, similar to DED.

What to do about it

There is no cure for elm yellows. Management focuses on preventing spread.

• Remove infected trees promptly to eliminate them as a phytoplasma reservoir.
• Trench to sever root grafts with neighboring elms before removing the infected tree.
• Insecticide applications targeting leafhoppers can reduce vector populations, but this is mostly a commercial-orchard scale intervention rather than a backyard one.
• Tetracycline injections by certified arborists can slow elm yellows in early infections, though they don’t cure the disease.

How to keep it from coming back

Like DED, prevention is mostly about cultivar choice on new plantings. The DED-resistant cultivars listed above also tend to have some resistance to elm yellows, though the resistance is not as well-established. Asian elms (Ulmus parvifolia, U. japonica) appear more resistant to elm yellows than American elms.

Elm anthracnose

Elm anthracnose is caused by several fungal species (Stegophora ulmea being the most common in the Midwest and Northeast). It’s a foliar disease that produces leaf spots and twig dieback in cool wet springs. Compared to DED and elm yellows, anthracnose is a manageable nuisance rather than a tree-killing emergency.

What it looks like

Small dark brown to black irregular spots on leaves, appearing on the upper surface in late spring. Heavy infections cause leaves to twist, yellow, and drop early. Some forms of anthracnose also produce small twig cankers and shoot dieback, but the disease rarely progresses to major branches.

The damage is mostly cosmetic. Trees typically push a second flush of leaves after the initial infection drops, and the second flush is usually clean.

What to do about it

For most backyard elms, anthracnose is not worth chasing with fungicide. Two passive controls handle it:

• Rake fallen leaves in autumn. The fungus overwinters in leaf litter.
• Improve air circulation by selective interior pruning if the tree is dense and shaded.

If anthracnose has been severe for 2-3 consecutive years, a copper or chlorothalonil fungicide applied at bud break and again 14 days later can suppress new infections. Most homeowners find the tree manages on its own.

Bacterial leaf scorch

Bacterial leaf scorch is caused by Xylella fastidiosa, the same bacterium that causes Pierce’s disease in grapes and bacterial leaf scorch in oaks. The bacteria live in the xylem (water-conducting tissue) and gradually clog it, producing characteristic scorched leaf margins.

What it looks like

Marginal leaf browning, often with a distinct yellow band of tissue between the brown scorched edge and the healthy green leaf tissue near the midrib. The yellow halo is the diagnostic feature: environmental drought scorch produces brown margins without the yellow halo.

Per University of Maryland Extension, bacterial leaf scorch symptoms first appear on the lower branches and on the older interior leaves, progressing from older to younger leaves over the season. As the disease progresses over several years, branches die and the tree gradually declines.

Why it happens

The bacterium is vectored by xylem-feeding insects: leafhoppers, sharpshooters, and spittlebugs. The insects pick up bacteria feeding on infected trees and transmit them during feeding on healthy trees.

Once Xylella is established in a tree, it cannot be eradicated. The bacteria gradually colonize more of the xylem system, reducing water transport and eventually killing the tree over 5-10 years.

What to do about it

There is no cure. Management focuses on prolonging the tree’s productive life:

• Maintain tree vigor with consistent watering and proper fertilization. A well-watered tree compensates for partially blocked xylem better than a stressed one.
• Prune out dead and severely declining branches to reduce stress on the rest of the tree.
• Oxytetracycline injections by certified arborists can delay symptoms in some trees. Treatment must be repeated annually and the trees still eventually decline.
• Plan for eventual removal. A bacterial-leaf-scorch-positive elm will likely need removal within 5-10 years. Budget for it.

Elm leaf beetle

Elm leaf beetle (Xanthogaleruca luteola) is the most common elm pest. It can defoliate trees but rarely kills them.

What it looks like

Two distinct damage patterns from the two life stages:

• Larvae (dark grub-like, up to 1/2 inch long) feed on the underside of leaves, skeletonizing the leaf between the veins. Heavily damaged foliage looks lacy and turns brown.
• Adult beetles (1/4 inch, yellowish with dark stripes) chew irregular round holes in the center of leaves.

In bad years, an entire tree can be partially or completely defoliated by mid-summer. Trees typically push a second flush of leaves and recover, but multiple consecutive years of severe defoliation weaken the tree.

Why it happens

Adults overwinter under bark, in leaf litter, and in nearby structures. They emerge in spring as elm leaves expand and lay yellow eggs on the underside of leaves. Larvae hatch in 7-10 days, feed for several weeks, then crawl down the trunk to pupate at the base. Adults emerge in summer and start a second generation, which is often the more damaging cycle.

What to do about it

Multiple options depending on infestation severity:

• Soil drench with imidacloprid in early spring before egg-laying. The systemic insecticide reaches the leaves where the larvae feed.
• Foliar sprays with insecticides targeting larvae are effective during the egg-hatch window (about 2 weeks after eggs appear). Pyrethroid or spinosad products work.
• Trunk banding with sticky barriers or contact insecticide can intercept larvae as they move down the trunk to pupate. Both generations can be intercepted with bands applied at the right time (typically June and August).
• Bacterial insecticide (Bacillus thuringiensis var. tenebrionis) is selective for leaf beetles and safe for beneficial insects. Apply when larvae are small and actively feeding.

For backyard elms, most homeowners can manage elm leaf beetle without intervention. The tree defoliates, pushes new leaves, and continues growing. Intervention is most warranted on stressed or recently planted trees that can’t afford a year of poor growth.

When to call an arborist

Elm diseases warrant professional involvement more often than most tree diseases. Three situations are particularly important.

First, suspected Dutch elm disease on any mature American elm. Confirmation through lab testing matters, and the trunk injection treatment (if applicable) is professional-only work. Catching DED early can preserve the tree; catching it late means removal becomes the only option.

Second, a mature elm with multi-year decline where you can’t distinguish between DED, elm yellows, bacterial leaf scorch, and elm anthracnose. The treatments differ and lab testing through a university plant diagnostic clinic ($30-100) settles the question.

Third, multiple elms in a row showing matching symptoms, where root graft severing decisions matter to protect the rest of the row.

An ISA-certified arborist consultation runs $75-200 in most US markets. Find one through the Trees Are Good arborist locator or read our guide to what an arborist does before you call.

For confirmed DED or elm yellows trees that need to come out, tree removal on a mature elm typically runs $1,500-5,000 depending on size and proximity to structures. Elms get large, and removing a 70-foot specimen near power lines is expensive.

Should you plant an elm at all?

This is the most common question and the answer has changed dramatically over the last 20 years.

For most of the 20th century, the answer was no. Dutch elm disease killed every American elm planted in any DED-pressure region within 10-20 years of planting. The advice in our never plant this tree in your yard guide historically included American elm for exactly this reason.

The modern answer is yes, but plant a resistant cultivar. Princeton, Valley Forge, New Harmony, and Lewis and Clark are dependable choices for new plantings even in active-DED regions. They produce the same classic vase-shaped canopy that made American elms beloved as street trees, but they survive what kills susceptible elms.

For yards that need a fast-growing shade tree on a 30-year horizon, a resistant elm is one of the best choices available. Our fast growing trees guide covers other options for homeowners who want shade quickly, but the resistant elms compare favorably for ultimate canopy size and longevity.

Prevention checklist

Five habits handle most elm tree issues for new and existing plantings:

• Plant resistant cultivars only. For new plantings, choose Princeton, Valley Forge, New Harmony, Lewis and Clark, or one of the hybrid cultivars (Accolade, Triumph, Patriot, Frontier). Old non-resistant Ulmus americana seedlings, despite being native, are almost guaranteed to die from DED in any pressure region.
• Don’t move elm firewood. Bark beetles emerge from cut elm wood. Moving infected logs spreads DED across regions.
• Walk the tree every June for the wilting-branch signature of DED. Early detection is the only thing that preserves an infected tree.
• Maintain tree vigor with proper watering, mulching, and avoidance of trunk wounds. Stressed elms are more vulnerable to every disease in this guide.
• Annual late-winter pruning to remove dead and dying branches, sanitize tools between cuts. Dead elm wood is the bark beetle’s egg-laying habitat.

For broader fungal disease patterns across the rest of your yard, see our tree fungus guide. For other large-canopy native shade trees that could substitute for elm in a yard with poor DED resistance options, the fast growing trees and types of trees guides cover oaks, maples, and other options.

Frequently asked questions

Can I plant an American elm safely today?

Yes, if you choose a resistant cultivar. Princeton, Valley Forge, New Harmony, and Lewis and Clark are genetically Ulmus americana but have been bred for Dutch elm disease resistance. They produce the same classic vase-shaped canopy as the historic American elms. Avoid seedling American elms or unnamed nursery stock; insist on a named resistant cultivar.

What kills American elm trees most often?

Dutch elm disease (DED), caused by Ophiostoma novo-ulmi and transmitted by elm bark beetles. DED killed millions of American elms across North America in the 20th century and continues to kill susceptible trees today. Elm yellows is the second most lethal disease. Bacterial leaf scorch causes slower decline but eventually kills susceptible trees. Elm anthracnose and elm leaf beetle are usually survivable.

Can a mature elm be saved from Dutch elm disease?

Sometimes, with professional intervention. Trunk injections with fungicides (Arbotect, propiconazole) prevent DED in healthy trees and can suppress early infections. Sanitation pruning (cutting 10+ feet below the lowest symptom) sometimes saves trees caught in single-branch early infection. By the time DED has reached multiple branches, the tree is usually finished. Treatment is professional-only and runs $200-1,000+ per tree per cycle.

What’s the difference between Dutch elm disease and elm yellows?

Both kill American elms but they have different signatures. DED produces a sudden wilting on one branch first, with brown streaking in the sapwood under the bark of affected branches. Elm yellows produces gradual yellowing across the whole crown in mid-to-late summer, with butterscotch-brown discoloration of the inner bark visible at the trunk level (not just on branches). DED is caused by a fungus and spread by bark beetles. Elm yellows is caused by a phytoplasma and spread by leafhoppers.

Do I need to remove a tree with bacterial leaf scorch immediately?

No, but plan for eventual removal. Bacterial leaf scorch progresses over 5-10 years. Treatment with oxytetracycline injections can delay symptoms but doesn’t cure the disease. Maintaining tree vigor extends the useful life. Severe decline (more than half the canopy dead) typically signals the time for removal before structural failure becomes a risk.

Are elm diseases contagious to other trees?

DED is elm-specific. Elm yellows is elm-specific. Elm anthracnose is elm-specific (though similar anthracnose diseases hit other species). Bacterial leaf scorch (Xylella fastidiosa) crosses many tree species including oaks, sycamores, and grapevines, with strain differences affecting which hosts are susceptible. Elm leaf beetle is elm-specific.

Why don’t I see American elms in cities anymore?

Most mature American elms in North America were killed by Dutch elm disease between 1930 and 1980. The few surviving mature trees are in places where the disease hasn’t reached or where aggressive injection programs have kept them alive. The species hasn’t disappeared, but its dominance as a street tree has been replaced by oaks, maples, and other species. Modern resistant cultivars are slowly being replanted in cities that committed to long-term restoration, but the loss of the original urban elm canopy was a generational event.

What’s the best fast-growing shade tree if I can’t grow elm?

If a resistant elm doesn’t fit your site or you want alternatives, our fast growing trees guide covers options including American sweetgum, tulip poplar, dawn redwood, and several oak species. None grows quite as fast as Siberian elm (which we don’t recommend due to weak wood and invasive tendencies), but several reach mature shade-tree size within 15-25 years.