TREE HEALTH GUIDE • BISMARCK, ND
Emerald Ash Borer in Bismarck: What Homeowners Should Do
Yes, emerald ash borer (EAB) is in Bismarck. City forestry crews found it in late August 2026 while removing declining ash trees near Interstate Loop. It was the first find in central North Dakota, and Burleigh County is now under a state quarantine.
If you own an ash tree, here’s the short version. Confirm it’s really an ash. Check how healthy it is. Then decide whether to treat it, remove it or keep watching it. There’s no need to panic. EAB spreads slowly on its own, and most people have time to make a good choice.
If storms leave a tree unsafe, see our storm cleanup service.
What Happened
What Happened: EAB Found in Bismarck in August 2026
| When | What happened |
|---|---|
| Since 2008 | The City of Bismarck cut ash from 36% to 22% of its boulevard trees |
| Before 2026 | EAB had been found in Cass and LaMoure counties in eastern North Dakota |
| Week of August 26, 2026 | Bismarck city forestry staff found EAB near Interstate Loop while removing declining ash |
| Late August 2026 | The North Dakota Department of Agriculture added Burleigh County to the EAB quarantine |
| September 2026 | The Bismarck Landfill stopped giving out and selling firewood |
| September 2026 | The city laid out its plan to treat about half its boulevard ash and remove the rest |
Bismarck still has about 5,200 ash trees on city boulevards alone, and many more grow in backyards, parks and shelterbelts.
Read about ash-lined streets in older central Bismarck neighborhoods.
UNDERSTANDING THE PEST
What Is Emerald Ash Borer?
Emerald ash borer is a small, metallic green beetle, about half an inch long. The adults do little harm. The damage comes from the larvae, which tunnel under the bark and cut off the flow of water and nutrients through the tree.
According to NDSU Extension:
- Adults fly from mid-June to mid-July, with the peak in mid to late July in North Dakota.
- Larvae feed under the bark from late June through October.
- In a cold state like North Dakota, one generation can take two years.
- Once larvae numbers are high, a tree usually dies within 2 to 5 years, depending on its size and health.
EAB spreads only 1 to 2 miles a year on its own. It travels much farther in firewood and ash logs moved by people, which is why the quarantine exists.
ASH TREE IDENTIFICATION
Do You Have an Ash Tree?
Before you worry, make sure the tree is actually an ash. NDSU’s ash identification guide lists these features:
- Branches and buds grow directly across from each other, not staggered along the twig.
- Leaves are compound, with 5 to 11 leaflets that have finely toothed edges.
- Bark is smoother with an orange tint on young trees, and gray with diamond-shaped ridges on older ones.
- Seeds are single, winged seeds that hang in clusters and often stay on the tree into winter.
Green ash is by far the most common ash in North Dakota yards, shelterbelts and city streets. It’s the one most Bismarck homeowners have.
Trees That Look Like Ash but Aren't at Risk
| Tree | How to tell it from ash | At risk from EAB? |
|---|---|---|
| Mountain ash | Leaves staggered along the twig, red-orange berries instead of winged seeds | No, it isn’t a true ash |
| Boxelder | Only 3 to 5 leaflets, seeds in pairs | No |
| Black walnut | 9 to 15 leaflets, staggered along the twig | No |
| Amur corktree | Up to 13 shiny leaflets, different fruit | No |
Mountain ash is the one people mix up most. NDSU confirms it can’t get EAB because it’s not a true ash.
KNOW THE SIGNS
Signs Your Ash Tree May Have Emerald Ash Borer
The North Dakota Department of Agriculture lists six signs:
- 01
Thinning leaves in the upper canopy, often starting at the top
- 02
Leafy sprouts growing from the trunk or main branches
- 03
Bark splitting, often in vertical cracks
- 04
Woodpecker damage, with light patches where outer bark has been chipped off
- 05
S-shaped tunnels under the bark, packed with fine sawdust
- 06
D-shaped exit holes, about 1/8 inch across, where adults came out
Woodpecker damage is easiest to see in winter, when the leaves are off. The thinning canopy shows best in summer. One sign alone doesn’t prove EAB, since drought, storms and other pests can also thin an ash. Two or more together are worth a closer look.
OFFICIAL REPORTING
How to Report a Suspect Ash Tree in North Dakota
If you think your ash has EAB, the state wants to know. The North Dakota Department of Agriculture takes reports three ways:
- 01
Online: the Report a Suspect Ash Tree form
- 02
Phone: North Dakota Agriculture reporting hotline, option 2
- 03
Email: ReportAPest@nd.gov
State or local staff will follow up. For a boulevard tree, you can also contact the City of Bismarck Forestry Division.
MEASURING YOUR TREE
How to Measure Your Ash Tree
Treatment choices and prices depend on trunk size, so it helps to know yours.
- 01Measure 4.5 feet above the ground. That’s the standard height for trunk diameter.
- 02Wrap a tape measure around the trunk to get the circumference in inches.
- 03Divide by 3.14 to get the diameter.
For example, a trunk that measures 47 inches around is about 15 inches across. At that size, NDSU says it’s time to call a professional instead of treating it yourself.
COUNTY QUARANTINE
Burleigh County Quarantine: Rules for Ash Wood and Firewood
Under the state quarantine, you can’t move these out of Burleigh County without a permit:
- Ash logs, limbs, branches and roots
- Ash wood chips
- Nursery stock
- Hardwood firewood of any kind
Civil fines can reach $5,000. A few local points that catch people off guard:
- Mandan is in Morton County, which wasn’t part of the quarantine as of September 2026. Hauling ash wood from Bismarck across the Missouri River to Mandan means taking it out of Burleigh County.
- The Bismarck Landfill stopped giving out and selling firewood in September 2026.
- Heat-treated firewood that meets the state standard of 140°F for at least 60 minutes, and is labeled that way, is the safe choice for camping trips.
- Buy firewood where you burn it. Don’t haul it to the lake or cabin.
If you’re removing an ash, decide where the wood goes before the tree comes down.
Learn about ash trees in Mandan and the rules for burning firewood in a backyard fire pit.
CITY RESPONSE
What the City of Bismarck Is Doing About Its Ash Trees
The city has been planning for EAB for years. It cut boulevard ash from 36% to 22% of its street trees since 2008. Now that EAB is here, KFYR-TV reported in September 2026 that the city plans to:
- 01
Treat about 2,600 boulevard ash trees over 3 years
- 02
Remove the other 2,600 over 4 years
- 03
Replace the removed trees
Bismarck’s city forester told residents, “You’ve got time.” Finding EAB in town doesn’t mean every ash has to come down this year.
The trees on the boulevard, between the sidewalk and the curb, belong to the city. Don’t treat, prune or remove a boulevard ash on your own. The city requires a permit for pruning or removal, and it’s handling boulevard ash under its own plan. Contact the City Forestry Division with questions about the tree in front of your house.
See our guide to boulevard tree permits before arranging work.
YOUR ACTION PLAN
A Simple EAB Plan for Bismarck Homeowners
- 01
Walk your yard. Find every ash on your property using the ID checklist above.
- 02
Rule out mountain ash and other look-alikes.
- 03
Measure each trunk at 4.5 feet and note it down.
- 04
Rate each tree’s health. How much of the top is thin or bare?
- 05
Pick an option for each tree: treat, remove or watch.
- 06
Plan for the wood under the quarantine before any removal.
- 07
Plan the replacement. Choose a mix of trees that handle Bismarck’s alkaline clay, and skip maples, which the city lists among its top removals.
- 08
Check again every season, especially in summer when thinning shows best.
Young and newly planted trees also need deep watering before the ground freezes. Our fall yard checklist for Bismarck covers the timing.
For local replacement choices, see trees to replace ash.
Questions
Emerald Ash Borer in Bismarck FAQ
Straight answers about identification, treatment, reporting and ash wood rules.
Have a question that isn’t here?
Read more tree health guidance and common EAB questions in our FAQ.
Is emerald ash borer in Bismarck?
Yes. Bismarck city forestry staff found emerald ash borer in late August 2026 near Interstate Loop. It was the first find in central North Dakota, and Burleigh County was added to the state’s EAB quarantine.
How long does it take emerald ash borer to kill a tree?
Usually 2 to 5 years once larvae numbers are high, depending on the tree’s size and health, according to NDSU Extension.
Can I save my ash tree?
Often, yes. A healthy ash with less than about 40% of the canopy dead can be protected with insecticide. Trunk injections of emamectin benzoate protect a tree for about 2 to 3 years at a time. Trees with more than 40% decline aren’t likely to recover.
Does emerald ash borer attack mountain ash?
No. Mountain ash isn’t a true ash, so EAB doesn’t attack it. You can tell it apart by its staggered leaves and red-orange berries.
Can I treat my ash tree myself?
For smaller trees, yes. NDSU lists an imidacloprid soil drench in spring and a dinotefuran bark spray as homeowner options. Trees more than 15 inches across should be treated by a professional.
Can I burn or give away ash firewood in Bismarck?
You can burn it where it is, but you can’t move ash wood or any hardwood firewood out of Burleigh County without a permit. Fines can reach $5,000. That includes hauling it to Mandan, which is in Morton County.
Should I treat or cut the ash tree on my boulevard?
No. Boulevard trees belong to the City of Bismarck, and the city is treating or removing them under its own plan. Pruning or removing one requires a city permit. Contact the City Forestry Division.
Read our full tree and EAB FAQ for more answers.
How do I report emerald ash borer in North Dakota?
Use the North Dakota Department of Agriculture’s online Report a Suspect Ash Tree form, contact the state reporting hotline and choose option 2, or email ReportAPest@nd.gov.
Bismarck Landscape
Need Help With an Ash Tree?
If you’re not sure whether your ash is worth saving, we’ll take a look and give you a straight answer on treating, removing or waiting.
Contact Bismarck Landscape, or see our other contact options. For more local answers, visit our FAQ.