If caught early enough, immediately apply Multi-Insect Killer Tree Injection Kit to the tree. This insecticide is injected directly into the tree’s vascular system and released quickly, to help control insects already inside the vascular system.
To prevent repeated Ash Borer attacks, and in areas of known Ash Borer activity, a number of steps can be taken to prevent attacks in healthy trees. In the early spring, treating the tree with Once-A-Year Insecticidal Drench w/Merit helps protect the tree’s vascular system. This treatment can be supplemented by regularly spraying the tree’s trunk with a good dose of Borer-Miner Killer (every three to three weeks), thus creating a barrier to reduce further insect penetration through the bark.
The good news is that healthy and well-maintained trees are normally more resistant to the Emerald Ash Borer, so they’re less of a target. Trees under stress are more likely to be borer targets, so it is important to ensure that Ash trees receive adequate water. To help ensure that a tree is healthy, apply a TreeHelp Annual Care Kit for Ash in the spring or early summer which contain the appropriate fertilizer.