09/01/2026
Meet the emerald ash borer: small, metallic green, and one of the most destructive pests to hit Colorado's ash trees. Adults emerge in late spring through summer, but it's the larvae underneath the bark doing the real damage, cutting off the tree's ability to move water and nutrients. Signs to watch for include thinning canopy, D-shaped exit holes in the bark, and increased woodpecker activity. If you have an ash tree on your property, now's the time to know the signs of infestation, catching it early makes all the difference in whether a tree can be saved.