How To Treat Ash Trees For Emerald Ash Borer

Emerald Ash Borer Treatment Sick Ash Tree? June 1, 2020 Gudenkauf
Emerald Ash Borer Treatment Sick Ash Tree? June 1, 2020 Gudenkauf from

The Emerald Ash Borer Infestation

Ash trees are facing a serious threat from the emerald ash borer, an invasive beetle species that is causing significant damage to ash tree populations across North America. The beetle larvae feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients, eventually leading to the tree’s death if left untreated. If you have ash trees on your property, it is crucial to take action to protect them from this destructive pest.

Identifying Emerald Ash Borer Infestation

Before you can start treating your ash trees, it is important to confirm that they are indeed infested with emerald ash borers. Look out for signs such as D-shaped exit holes in the bark, S-shaped tunnels under the bark, and thinning or dying canopy. If you suspect an infestation, it is recommended to consult with a professional arborist or a local extension office for an accurate diagnosis.

Treatment Options

1. Insecticide Treatment

The most common method of treating ash trees for emerald ash borers is through insecticide treatments. These treatments can be administered by a professional arborist or with DIY products available in the market. There are two types of insecticide treatments: systemic and foliar. Systemic treatments are applied to the soil around the tree, and the insecticide is absorbed by the roots and transported throughout the tree, killing the borers as they feed. Foliar treatments, on the other hand, are sprayed directly on the tree’s foliage, targeting the adult beetles.

2. Biological Control

Another treatment option is biological control, which involves introducing natural enemies of the emerald ash borer to help control their population. One such biological control method is the release of parasitoid wasps, which lay their eggs inside the beetle larvae, eventually killing them. This method is more environmentally friendly but may take longer to show results.

Implementing Treatment

When implementing treatment, it is important to follow the instructions provided by the product manufacturer or seek professional advice. The timing of the treatment is crucial, as it should be done when the beetles are most vulnerable, typically during the spring or fall. Regular monitoring of the tree’s health and reapplication of treatments may be necessary to ensure long-term protection.

Preventive Measures

Prevention is key to protecting ash trees from emerald ash borers. Avoid transporting firewood from infested areas, as the beetles can hitch a ride on the wood and spread to new locations. Keep your trees healthy by providing proper watering, fertilization, and pruning. Regularly inspect your trees for signs of infestation and take immediate action if you suspect an issue.


The emerald ash borer poses a significant threat to ash trees, but with proper treatment and preventive measures, it is possible to protect and preserve these valuable trees. Whether through insecticide treatments or biological control methods, early detection and action are crucial. Consult with professionals and stay updated on the latest research and recommendations to effectively treat ash trees for emerald ash borers and ensure their long-term health and survival.