Emerald ash borer (Agrilus planipennis) was discovered in Minnesota in 2009. Ever since, it has been expanding its area. Emerald ash borer is an invasive species of beetle that is a highly destructive pest of ash (Fraxinus) trees.
In 2017, Emerald ash borer was discovered about a mile from our property and more extensive infestations where found in 2019. I considered having our ash trees removed at that time but I had other more pressing concerns when the COVID pandemic hit in 2020. With the assistance of the resident woodpeckers, I made positive identification of Emerald ash borer infestations in our ash trees this spring (May 2022) but I had already had suspicions the previous fall.
We have an acre of land with 15-20 ash trees, all of which are infested and dying or are already dead. I requested estimates from several tree removal companies. I chose Davey Tree in South St Paul who will remove the ash trees in January.
Fortunately, only two ash trees are near our house. Neither provides significant shade on the house in the summer, so their loss will be minimal. The other remaining ash trees are clustered on south end of our property. They are largely screened from view by maple trees. However, their loss will be felt because the shaded they provided kept the common buckthorn (Rhamnus cathartica) at bay. I foresee increased effort upon my part to remove buckthorn from our property.
I’ll replace the two ash trees near the house with Kentucky coffeetrees (Gymnocladus dioicus) and the other ash trees with a mix of black walnut (Juglans nigra) and black cherry (Prunus serotina) trees. Black walnut will do well as I am frequently removing saplings from inopportune locations, most likely planted there by the resident gray squirrels. And there are numerous Kentucky coffeetrees in a county park located a few miles away. I was unable to find any black cherry trees while taking Lizzie for a walk through the neighborhood in search of them. I believe I have seen them around, I just don’t remember where I saw them. An article in Minnesota Conservation Volunteer, published by the Minnesota Department of Natural Resources (DNR), states that Minnesota is becoming more suitable for black cherry due to climate change.
I’m grateful none of our oak trees are impacted by pests or diseases. Oak trees provide all of the summer time shade on our house, keeping it significantly cooler during the summer. There is a noticeable difference in temperature between the unshaded and shaded portions of the front yard. On hot summer days, the unshaded portion is 10℉ warmer than the shaded portion. I’ve been keeping a close watch on our oak trees and have been diligently watering them during the drought we have been experiencing for the last two years. Our neighbors have an oak in their back yard that was killed by oak wilt. I intend on contacting Davey Tree to inquire with them what preventative steps I can take to protect our oak trees. I don’t want to lose them.