These birch were planted spring of 2022 and the largest has had the top canopy die off. There are raised ridges on the trunk, so it may have bronze bi...
Bronze birch borer #851205
Asked September 25, 2023, 4:07 PM EDT
These birch were planted spring of 2022 and the largest has had the top canopy die off. There are raised ridges on the trunk, so it may have bronze birch borer. Is it possible to save the smaller tree that still looks healthy? What should I do about the larger one with the damaged canopy?
Grand Traverse CountyMichigan
Hi Susan, The smaller tree can be treated for the bronze birch borer to prevent damage. Is the property/tree on or near a lake? If not, you may use the systemic insecticide, which involved mixing the solution and pouring it around the base of tree so that the insecticide can be taken up by the roots of the tree next spring. If the tree is near a lake, then you'll have to hire an arborist to do a basal bark treatment next spring. The article below explains the process and recommended active ingredients. Also, be sure to keep the tree watered when no rain. Allowing the hose to run under the tree for an hour 1-2 times a week will suffice. https://extension.entm.purdue.edu/publications/E-50/E-50.html
Because the damage is in the trunk of the larger tree, it is too late to save. That tree should be removed and replaced if desired. The article at the link below mentions options that are more resistant to the birch borer. https://www.canr.msu.edu/resources/bronze_birch_borer
This work is supported in part by New Technologies for Ag Extension grant no. 2020-41595-30123 from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.