News > Emerald Ash Borer Wreaking Havoc in Stearns Electric Service Territory

Emerald Ash Borer Wreaking Havoc in Stearns Electric Service Territory

April 24, 2023

EMERALD ASH BORER (EAB) IS AN INVASIVE INSECT PEST OF ASH TREES. EAB ATTACKS ALL SPECIES OF NORTH AMERICAN ASH TREES, WHICH ARE COMMON IN CENTRAL MINNESOTA. IN 2019, EAB WAS DISCOVERED IN CLEARWATER AND SAUK CENTRE. MORE RECENTLY, THE COOPERATIVE HAS IDENTIFIED THOUSANDS OF INFESTED AND DEAD ASH TREES IN POCKETS OF OUR SERVICE AREA AND WE ANTICIPATE THAT NUMBER TO CLIMB QUICKLY OVER THE NEXT SEVERAL YEARS.

Emerald Ash Borer (EAB) is a native insect of Asia. It was first detected in the United States in 2002 and in Minnesota in 2009. EAB attacks ash trees of all sizes. Once an ash tree is infested with EAB, it will die if the tree is unprotected. Over time, experts predict EAB will eventually kill all the country’s ash trees if they are not treated with a specific EAB insecticide. Minnesota is home to nearly one billion ash trees, including about 16 million in Stearns County alone.

EAB moves approximately one-half to one mile per year from infested sites. It has spread faster though as people can carry it hundreds of miles when transporting firewood and other wood products, according to the University of Minnesota.

On average, ash trees can grow between 40-60 feet, with some species reaching 80 feet in height. Infested or dead trees of these heights are considered danger trees to the Cooperative’s Right-of-Way (ROW).

Since 2019, our ROW tree clearing planners have detected EAB sporadically throughout our system. As the years go by it has become more and more prevalent. Recently we completed planning in the Grand Lake area near Rockville and identified hundreds of infested and dead ash trees. Because the infestation is so serious, Stearns Electric needs to update its policies regarding ROW tree clearing and infested ash trees. If we don’t take these steps, it will become very costly for the Cooperative and our member-owners.

Currently, the Cooperative manages the ROW on a four-year tree clearing cycle. We plan to continue our normal cycle, clearing danger trees and brush out of the ROW distance. However, if an ash tree is identified as at least 30% infested or dead within the normal ROW, or outside of the normal ROW clearing distance but is a threat to our primary power lines, the Cooperative’s tree clearing crews will top (or cut) the tree to below our power lines. The remaining tree and cleanup are left to the property owner to take care of.

Trees that are infested and identified as a threat to our secondary power lines, even if in the ROW distance, will be the responsibility of the property owner.

In some cases, Stearns Electric will offer to temporarily drop the primary or secondary power lines to allow property owners or their tree contractor to safely remove trees that are outside the normal ROW clearing distance.

The Cooperative has identified thousands of infested and dead ash trees in pockets of our service area and we anticipate that number to climb quickly over the next several years. Because the infestation is so serious, Stearns Electric needs to update its policies regarding Right-of-Way tree clearing and infested ash trees. If we don’t take these steps, it will become very costly for the Cooperative and our member-owners.

If an infested or dead ash tree needs to be removed, here is a breakdown of responsibilities for members and Stearns Electric.

Visit our website, https://www.stearnselectric.org/account-services/service-requests/tree-trimming/, for more information on EAB, including a FAQ document for members. Contact the Cooperative at (800) 962-0655 during regular business hours with any questions.

Please note, our arborist will attempt to contact all property owners at least three times before any trees are removed on member property.