Bismarck's Forestry Division will spend the next several years treating and removing ash trees along city boulevards, the City of Bismarck said in an Oct. 28, 2026, announcement, following the confirmed discovery of emerald ash borer (EAB) in the city in August.
The plan
The City's Forestry "Hot Topics" page says Bismarck has approximately 5,200 ash trees on city boulevards. According to the Oct. 28 announcement:
- Removals: About half of the boulevard ash population will be removed over the next four to five years, prioritized by tree condition, structural concerns and public safety.
- Treatment: The remaining boulevard ash trees will be treated with insecticide on a three-year cycle. Some treated trees may still be removed in later years as conditions change; others will be treated for the life of the tree.
- Replanting: The City says it will replant wherever space and infrastructure allow. A detailed replanting plan is still being finalized, and more information will be shared as plans develop.
The Hot Topics page adds that the long-term goal is to reduce ash to about 10% of the total boulevard tree population.
The plan covers only ash trees on boulevards in the public right of way, the City says.
"This plan allows us to manage EAB responsibly by combining treatment with phased removals so impacts are gradual, not sudden," City Forester Christy Ames Davis said in the announcement.
How far it has spread
The full extent of the infestation within Bismarck is not yet known, and surveys will continue, according to the City's Hot Topics page. The North Dakota Department of Agriculture's EAB page says the insect has been detected in LaMoure, Cass and Burleigh counties and that an infested ash tree can die in as little as two years.
What you can do
- Boulevard ash near your home: The City encourages residents to contact the Forestry Division if they think a boulevard ash tree near their property may be a candidate for removal or treatment. Call 701-335-1700, option 3, or email publicworks@bismarcknd.gov.
- Suspect a sick ash tree: The City notes it is not uncommon for ash trees to decline for reasons other than EAB, but encourages reporting symptomatic trees through the state's online Report a Suspect Ash Tree survey, or by emailing ReportAPest@nd.gov.
- Firewood: The state agriculture department asks people not to bring firewood into North Dakota.
Sources:
- City Shares Initial Emerald Ash Borer Management Approach After August Detection — City of Bismarck, Oct. 28, 2026
- Forestry Hot Topics — City of Bismarck Forestry Division
- Emerald Ash Borer — North Dakota Department of Agriculture