Tree problems · Disease

Dutch elm disease: signs and what to do

Dutch elm disease is a tree disease, often seen on American elm, Siberian elm, lacebark elm. Look for: sudden wilting and yellowing of leaves on one branch, called flagging.

General information, not a diagnosis. A certified arborist or your county extension office can confirm.

Disease
American elm
Siberian elm (some resistance)
Lacebark elm (more resistant)

Signs to look for

Tick what you see. More ticks make it more likely, but only an on-site look can confirm.

Sudden wilting and yellowing of leaves on one branch, called flagging
Leaves that turn brown and stay on the branch
Brown streaks in the wood when you peel back the bark on an affected branch
Flagging that spreads to more branches over weeks
A tree that wilts quickly in early to mid summer
Elm bark beetle galleries under the bark of dying elms

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Season

Symptoms often show in late spring and summer. Bark beetles carry the fungus to healthy elms while feeding on twigs, and the disease can spread within a season.

How it spreads

Elm bark beetles carry spores from sick or dead elms to healthy trees. The fungus can also pass between neighboring elms through grafted roots.

Where it is found

Dutch elm disease has been found in most of the lower 48 states where elms grow, though local pressure varies. Check your state official map; ranges change.

Official sources

What to do

1
Check your elm for flagging branches in early and mid summer.
2
Take photos and contact your county extension office to ask about lab testing.
3
Ask a certified arborist about pruning out affected branches early, and about root-graft disruption if neighbors have elms.
4
Remove dead and dying elm wood promptly according to local advice, since bark beetles breed in it.
5
Clean pruning tools between trees and between cuts on a suspect tree.
6
Do not store elm firewood with the bark on.

Safety first: do not climb, do not cut near power lines and do not use a chainsaw on storm-loaded wood. Call the utility for downed lines and 911 if anyone is in danger.

Prevention

Remove dead elm wood so beetles cannot breed in it. Avoid heavy pruning during the beetle season on elms. Ask a certified arborist about preventive fungicide injection for high-value trees, which is not a guarantee and needs repeating. When replanting, choose resistant elm selections or other species. Community-wide sanitation works best.

When to call a pro

Call a certified arborist when you see flagging or a fast-wilting elm, and before removal of large elms near houses or streets. Elms are often big trees, so safe work needs trained, insured crews.

Not sure who to call? Read how to hire a tree service or check is my tree dangerous?

Trees it affects

Usually seen on: American elm, Siberian elm (some resistance), Lacebark elm (more resistant).

See all species in our tree library, or pick a tougher tree with the tree picker.

For tree companies

How to explain Dutch elm disease to a customer

Explain that Dutch elm disease is often managed at the neighborhood level, not just tree by tree. Be honest that early branch pruning works only in some cases, and that treatments are not guaranteed. Offer a simple plan: confirm, then treat, prune or remove.

Send this page to the customer after your visit so they can read the signs in plain words. See also selling plant health care and the job photo checklist.

Questions

What causes Dutch elm disease?

It is caused by a fungus that blocks the water-carrying tissue in elms. Elm bark beetles carry it from tree to tree.

How can I tell if my elm has it?

A common first sign is one branch whose leaves suddenly wilt and turn yellow or brown. Peeled bark on that branch may show brown streaks. Confirm with a lab through your extension office.

Can an infected elm be saved?

Sometimes, if the disease is caught early and only a small part of the crown is affected. Once it has spread through the tree, the chance is low. A certified arborist can judge your tree.

Are some elms resistant?

Yes. Some elm species and selections are more resistant than American elm. Ask a local nursery or arborist which ones are suited to your area.

Why should dead elm wood be removed?

Bark beetles breed in dead and dying elm wood and then carry the fungus to healthy trees. Prompt removal and proper disposal helps protect nearby elms.

Is fungicide treatment worth it?

For a high-value elm it can be an option, but it does not guarantee protection and must be repeated. Ask for the full cost and what results to expect.

Can Lirevon diagnose Dutch elm disease on my tree?

No. Lirevon is a remote marketing team for tree service companies and does not do tree work. This page is general information, not a diagnosis. A certified arborist or your county extension office can confirm what is wrong with your tree.

How do I find a good local pro for this?

Search Google Maps for certified arborists or tree services near you, read their reviews and ask for proof of insurance. Get two or three written quotes. Our guide on how to hire a tree service lists the questions to ask.

When customers spot Dutch elm disease, they call

Make sure someone answers. Missed-call text-back, lead follow-up, booking and review requests, set up for you. See our services and pricing.

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