Emerald Ash Borers in Louisville: How to Save Your Ash Trees

By Stephan Zimmerman

Adult EAB on a Penny (by Forest Service, USDA)

The Emerald Ash Borer (EAB) is a destructive insect that kills all ash trees it comes into contact with. In 2012, high populations of EAB were confirmed in the Louisville area. This pest from Asia was first detected in 2002 in Michigan, and in the decade since, it has spread to 15 US states and 2 Canadian Provinces. Up to now, EAB has killed over 25 million ash trees and threatens 10 billion more in the next decade. To put this disaster into context, Dutch Elm Disease has killed 200 million American elm trees in a 70 year span.

Now that EAB is here, what can we do about it? Ash trees have no natural defenses against EAB and the mortality rate of unprotected ash trees is 100%. Only ash trees protected with insecticides will survive.

There are a number of treatment options available for homeowners with ash trees, but not all treatments are the same. The first step in protecting your ash trees is to consult with a Certified Arborist. These professionals can help you identify your ash trees, and outline a long-term treatment plan for you. Many companies, including Limbwalker, provide this service free of charge. The valuable information you receive from a Certified Arborist will save you time, money, and your ash trees.

Ash Trunk Injectionwith Don Ovens

Insecticide treatments for protecting your ash trees fall into two categories: soil drench or trunk injection. Soil drenched insecticides are administered by pouring imidichloprid (a common insecticide used in flea medication) into the soil around your tree’s trunk. The tree roots uptake the chemical and distribute it to throughout the entire tree. Soil drenches do not injure the tree, but they must be repeated each year, and are less effective than trunk injections.

Trunk injected insecticides are delivered by drilling small holes at the base of the trunk, using pressurized containers to deliver a concentrated insecticide directly into the water-carrying cells of your tree. Trunk injections do involve minimal injury, but they are more effective, and protect your tree for a longer period of time than soil injections. The most effective chemical treatment on the market today is a product called Tree-age®. When injected into the trunk, it will protect your ash tree from EAB for two years or more. This is the only product that has been proven effective against EAB damage in heavy infestations.

Emerald Ash Borer will have a tremendous impact on Louisville’s ash tree for many years to come. To start protecting your ash trees, contact Limbwalker’s office to arrange a consultation with one of our Certified Arborists. Our consultations are always free, and we love talking about trees! Call Limbwalker at (502) 634-0400 or info@limbwalkertree.com.