What You Can Do

If You Have an Ash Tree

If you have an ash tree you need to evaluate and plan for their protection or removal. Your choice of actions and urgency will depend on factors that include the current health of the tree, the costs of treatment and removal, and how close you are to known infestations.

Planting a diverse urban forest makes it more resistant to pests.
Once a tree becomes infested it will die unless you are able to treat it soon after it becomes infested.

Managing Emerald Ash Borer: Decision Guide

Management

Within 10-15 miles of known infestation

If you have an ash tree on your property and you are within 10-15 miles of the known infestations you need to decide if you will remove or treat your ash trees.

Treatment needs to occur in spring to early summer. If you hire a contractor, they need to be licensed as a Commercial Applicator by the Colorado Department of Agriculture.

More than 15 miles of known location

If you have an ash tree on your property and you are more than 15 miles of the known infestations you should:

Monitor your trees and look for thinning in the upper canopy
Water regularly including winter and fall watering
You may want to plan on their eventual replacement with a different type of tree
If there are no signs of decline it is not necessary to treat unless there are other insect pests affecting your ash trees

Front Range Tree Recommendation List©

Insecticide Options for Protecting Ash Trees from EAB

Managing Emerald Ash Borer: Decision Guide

Control Options for EAB in CO

CSU Extension Fact sheet - Insecticides Used to Control Emerald Ash Borer on Residential Shade Trees – 5.626