---
title: Dutch Elm Disease | Northern Nevada Tree Guide
url: https://battleborntreeservice.com/tree-guide/dutch-elm-disease/
business: Battle Born Tree Service
address: 6301 US Highway 50 East, Carson City, NV 89701
phone: 775.232.8243
hours: Office Monday-Friday 8:30 am-5:00 pm; phones answered seven days a week; 24-hour emergency service
credentials: ISA Certified Arborist WE-11728A on staff; Nevada Business License # 20131580674; fully insured
type: Tree service (removal, crane work, pruning, stump grinding, defensible space, snow removal, firewood)
---

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- Dutch elm disease

# Dutch elm disease

Dutch elm disease is a fungal disease spread by elm bark beetles and root grafts, and its first sign is flagging: leaves on one upper branch curl, wilt and turn yellow or gray-green in summer. Only a lab test confirms it, and there is no recognized cure, so dead and dying elms are removed promptly because beetles breed in them.

- **Cause:** Two fungi, Ophiostoma novo-ulmi and O. ulmi

- **Hosts:** American and European elms

- **Spread:** By native and European elm bark beetles, and through root grafts between trees

- **First sign:** Flagging: upper-canopy leaves curl, wilt and turn gray-green or yellow

- **Confirmation:** Brown streaks under bark of a wilted branch; a lab test through Extension

Dutch elm disease is caused by the fungi Ophiostoma novo-ulmi and Ophiostoma ulmi. It is a serious disease of American and European elms, but wilting elms have other causes too, including drought and the elm leaf beetle. This page explains the signs, how it is confirmed and what pruning or removal looks like. Battle Born Tree Service does not spray, inject or apply products to trees. We identify the problem, prune out dead or hazardous wood and remove trees that cannot be saved.

## What are the signs of Dutch elm disease?

Montana State University Extension describes the first symptoms in summer, on branches in the upper canopy. The leaves curl, wilt and turn grayish-green or yellow, and the branch looks like a flag against the rest of the green crown. Nearby branches follow, and a tree can lose a large share of its canopy in a season. Drought can make the symptoms look worse.

The test that arborists use is the wood under the bark. When an arborist cuts into a flagging branch and peels the bark back, a diseased branch shows distinct brown streaks in the outer wood. Oklahoma State University Extension adds that samples must come from branches that are actively wilting and that show this discoloration, and that confirmation is by a laboratory through your county Extension office.

## How does it spread?

The fungi overwinter in infected elms and are carried to new trees by the native elm bark beetle and the European elm bark beetle. Beetles breed in dead and dying elms, so a dead elm left standing or a pile of elm wood with bark on it is a nursery for the carrier. The disease also moves through the roots: elms growing close together often have grafted roots, and the fungus passes through the graft from tree to tree. See [the Nevada rules on moving firewood](https://battleborntreeservice.com/guides/dont-move-firewood-nevada/).

## Which elms are involved?

The Montana State guide lists American and European elms as hosts. The elm on most old Northern Nevada lots is the Siberian elm, and the more common reason for a Siberian elm to look scorched in July is the elm leaf beetle or drought, not this disease. See [elm leaf beetle](https://battleborntreeservice.com/tree-guide/elm-leaf-beetle/) and [Siberian elm](https://battleborntreeservice.com/tree-guide/siberian-elm/). A diagnosis needs the wood and a lab, not the leaves alone. If you are unsure, take photos of the flagged branch and call [775.232.8243](tel:775.232.8243).

## What does an arborist check?

An arborist checks whether the wilting is on one branch or spreading, looks for brown streaking under the bark, and rules out other causes such as drought scorch or root damage. They also check whether nearby elms share roots and whether dead wood could harbor beetles or fall.

- Whether the wilting is confined to one branch or spreading, and its position in the crown
- Brown streaking in the wood beneath the bark of a symptomatic branch
- Signs of other causes: skeletonized leaves, drought scorch, root damage, a cankered trunk
- Whether other elms are close enough to share roots
- Dead or dying wood that could be a beetle breeding site and a falling hazard

## When is pruning or removal the answer?

Montana State's advice is to prune symptomatic branches promptly, and arborists disinfect their tools between cuts. A University of Idaho guide says there is no recognized cure for the disease and that pruning only helps when less than 10 percent of the tree is infected. So a tree with a single flagging branch caught early may be pruned and watched, but a tree with a large share of its crown wilted is unlikely to be saved.

Once an elm is dead, or is more than lightly infected, removal is the usual answer, and sooner is better because dead elm wood is where the beetles breed. A large dead elm is brittle and should come down in a controlled way; see [tree removal](https://battleborntreeservice.com/tree-services/tree-removal/) and [large tree removal](https://battleborntreeservice.com/tree-services/large-tree-removal/). Do not store the wood with the bark on near other elms. For permits, a city right-of-way tree needs the city first; see [tree rules by jurisdiction](https://battleborntreeservice.com/data/tree-rules-by-jurisdiction/).

### Sources

- [Montana State University Extension: Dutch Elm Disease (Guide to Pests, Problems and Identification of Ornamental Shrubs and Trees in Montana)](https://www.montana.edu/extension/Full_HTML_Pubs/a-guide-to-pests-problems-and-identification-of-ornamental-shrubs-and-trees-in-montana/diseases/dutch-elm-disease.html) (read October 17, 2026)
- [Oklahoma State University Extension: Dutch Elm Disease](https://extension.okstate.edu/programs/digital-diagnostics/plant-diseases/dutch-elm-disease) (read October 17, 2026)
- [University of Idaho Extension: Dutch Elm Disease, an Old Disease in a New Place](https://UIdaho.edu/-/media/uidaho-responsive/files/extension/topic/forestry/id2-dutch-elm-disease-an-old-disease-in-a-new-place.pdf) (read October 17, 2026)

### Talk to the office

[775.232.8243](tel:775.232.8243)

| Monday to Friday | 8:30 am - 5:00 pm |
|---|---|
| Saturday and Sunday | Office closed, phones answered |

Phones answered seven days a week. 24-hour emergency service.

[Free estimate](#quote)

### Keep reading

- [Elm leaf beetle](https://battleborntreeservice.com/tree-guide/elm-leaf-beetle/)
- [Siberian elm](https://battleborntreeservice.com/tree-guide/siberian-elm/)
- [Siberian elms: the tree on every old Nevada lot](https://battleborntreeservice.com/guides/siberian-elms-old-nevada-lots/)
- [Large tree removal](https://battleborntreeservice.com/tree-services/large-tree-removal/)
- [How to tell if a tree is dead or dying](https://battleborntreeservice.com/guides/is-my-tree-dead-or-dying/)

### Terms on this page

[Arborist](https://battleborntreeservice.com/glossary/arborist/) [Right-of-way](https://battleborntreeservice.com/glossary/right-of-way/)

[The full glossary](https://battleborntreeservice.com/glossary/)

## Questions people ask

Still have a question? Call [775.232.8243](tel:775.232.8243). Phones are answered seven days a week.

### How do I know if my elm has Dutch elm disease?

Look for flagging in the upper crown, then check for brown streaks under the bark of the wilted branch. Only a lab test confirms it, arranged through your county Extension office.

### Can Dutch elm disease be cured?

A University of Idaho guide says there is no recognized cure. Pruning may help only if less than 10 percent of the tree is infected.

### Does my Siberian elm have it if the leaves are brown?

Not necessarily. Brown, lace-like leaves in summer are more often elm leaf beetle damage, and drought also scorches elms.

### Should a dead elm be removed quickly?

Yes. Elm bark beetles breed in dead and dying elms, so a dead elm left standing helps the disease spread.