How to Spray Ash Trees for the Ash Borer

Old-fashioned insecticide sprayer

One of the most common and dangerous insects that attack ash trees is the emerald ash borer (EAB). Preventative measures, like trunk injections and soil drenches, are recommended, but these are not always enough to keep these nasty pests at bay. There are insecticide sprays, which you can purchase from garden centers, hardware stores and home improvement stores, that are recommended for use around mid to late June. This is about the time that mature emerald ash borers start taking flight and when trunk and foliage sprays will be most effective.

Difficulty:

Moderate

Instructions

Things You'll Need

• Insecticide
• Rubber gloves
• Safety goggles
• 5-gallon bucket
• Garden sprayer
• Face mask

1. Buy a spray-type insecticide that has cyfluthrin, bifenthrin, permethrin, carbaryl or acephate listed as the active ingredient. These chemicals are commonly used to prevent and get rid of emerald ash borers.

2. Put on rubber gloves and protective goggles. Dilute the insecticide with water as instructed on the packaging in a 5-gallon plastic bucket. Mix well to combine the chemical with the water.

3. Carefully pour the diluted insecticide into your garden sprayer's reservoir tank. Seal the tank, and set your sprayer to a medium spray setting.

4. Put on a protective face mask so that you don't inhale any of the insecticide. Spray the tree to coat the foliage and bark with the insecticide. Spray the trees again in mid July for added protection.

Tips & Warnings

• Take every precaution to protect your eyes and skin from these insecticides.

• Do not breathe in the insecticides.

• Avoid applying insecticide sprays on windy days to prevent the chemicals from blowing back onto you when you work.

References

• Michigan State University: MSU Evaluation of Insecticides to Control EAB Adults & Larvae
• Michigan State University: Control of Emerald Ash Borer Adults and Larvae with Insecticides
• Tree Care Industry Association: Emerald Ash Borer: Insecticide Options for Protecting Ash Trees and Their Effectiveness