Be Informed Before You Treat Your Ash Trees This Summer

EAB has not yet been found in Minnetonka, but experts agree that it will eventually spread throughout the metro area. The closest EAB-positive trees are in Minneapolis, roughly south of the Prospect Park neighborhood, about 13 miles from Minnetonka’s eastern border. As a result, many Minnetonka residents have decided to start preventative insecticide (pesticide) treatments. Individual trees can be treated with specific insecticides in order to kill or keep EAB from establishing in the tree. The current recommendation is to avoid the treatments until the pest has been found within 15 miles of your yard.

It’s up to you to determine whether pesticide treatments are the right choice for your trees, but it’s important to be educated about your options. The city strongly advocates for the proper application and strict adherence to the pesticide’s label instructions in order to limit adverse environmental impacts in our community.

Before you decide to treat, consider:

• Cost of removal and replacement of your ash tree vs. the financial cost of long-term pesticide treatments performed every year or two into perpetuity.
• Timeframe for a new tree to establish. Treatment may be used until the new tree establishes and reaches a certain height.
• Value of the ash tree, depending on its location and its effect on your property value, wildlife habitat, heating and cooling costs and shade to your yard.
• Health, condition, size and age of your tree. Does your tree have strong branch structure? Does it have wounds or visible decay (rotting wood)?
• Number of ash trees. You can opt to treat the best and leave the others untreated.
• Proximity of emerald ash borer-positive trees. Wait to treat until your yard is 15 miles from the closest EAB tree. At this time, only southwestern Minnetonka is farther than 15 miles.

Once you decide to treat, remember:

• Each type of pesticide works differently in terms of how the insect comes into contact with the active ingredient.
• Some pesticides are “do-it-yourself” and others must be professionally applied.
• Products are applied via trunk injection, soil injection, soil drench, bark spray or foliage spray.
• Most treatments must be applied once per year or once every two years. They must be repeated in order to remain effective.

If you decide to use homeowner products:

Follow the tips below from the Minnesota Department of Agriculture to protect our water quality.

• Don’t use soil-applied products or sprays within 25 feet of bodies of water, including channels to surface or groundwater such as storm drains, street curbs, ditches, sumps or well heads, ponds, wetlands, streams and lakes.
• Don’t use soil applications or sprays if heavy rainfall is predicted within 24 hours of a planned treatment.
• Don’t apply a soil application to ground that is saturated or frozen or to sloped surfaces where runoff is a risk.
• Do use only the recommended amount of insecticide for your tree’s size and do not apply it more frequently than is advised so excess chemical is not leached into the groundwater system.
• Do minimize drift of insecticidal sprays by applying the chemical on calm days. These sprays present exposure risks to surface water, children, pets and nearby flowering plants and their pollinators.

Research about EAB management is always developing. Information about effectiveness, environmental impacts, costs and methods are changing frequently. To stay informed, visit the Minnesota Department of Agriculture’s webpage on emerald ash borer at www.mda.state.mn.us/emeraldashborer.

To read about available insecticides or effectiveness studies, visit the chemical treatments for emerald ash borer page.

Courtesy: City of Minnetonka. The original article was posted on the city of Minnetonka website.