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Emerald ash borer #923696

Asked January 16, 2026, 1:46 PM EST

I have two ashes that I have consistently treated for many years. I'm wondering if the ash borer problem is still in existence and/or do you think I've built up enough protection that I don't need to continue to treat these two trees?

Ramsey County Minnesota

Expert Response


Emerald Ash Borer is still a threat in Minnesota. Unfortunately, it is not leaving us any time soon. EAB has killed millions of Ash trees in the eastern U.S. and as it is moving west, will kill more. Minnesota has a lot of Ash trees so the insect can feed very well here. Trees should be treated every two years to maintain protection. 

It’s expensive, I know, but necessary if you want to keep your mature Ash trees for a long time. 

Ramsey County is a quarantined area. 

There is some exciting new research being done using a fungi that is naturally occurring in Minnesota, but it will be years before we see how effectively we can use this in a targeted manner.

https://extension.umn.edu/tree-and-shrub-insects/emerald-ash-borer

https://twin-cities.umn.edu/news-events/fungi-minnesota-can-kill-emerald-ash-borer-beetles

https://www.dnr.state.mn.us/invasives/terrestrialanimals/eab/index.html

Deb Reierson Replied January 18, 2026, 1:13 PM EST

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