Ash borer - treatment

Asked July 3, 2020, 5:29 PM EDT

Hello - I live in Littleton, CO, and my local newspaper said that the Emerald Ash Borer is a problem.
How do I know if I should treat my Purple Ash? Can I treat it myself? How?

Thank you!
Pamela Hallaren

Arapahoe County Colorado

1 Response

While Emerald Ash Borer (EAB) will appear in Arapahoe County at some point, it has only been detected in Boulder, Superior, Broomfield, Westminster, and Berthoud (Larimer County).

Until EAB is found within 10 miles of Arapahoe County, preventive treatments are not recommended. There is no benefit to using a preventive insecticide for an insect that is not present in the area. Some of the EAB-preventive insecticides pose significant risk to pollinators, including insecticides that are even available to homeowners.

The Colorado Department of Agriculture follows the progression of EAB in Colorado at:

When Emerald Ash Borer is present in Arapahoe County, the website above has some good information including a Homeowner Decision Guide on whether to treat your ash trees or remove them. There is also a good article written by the Horticulture Agent in Arapahoe County: