What is happening to my tree?

Asked May 10, 2019, 3:33 PM EDT

Any thoughts on what is happening to my Ash Tree? Why is the bark splitting and peeling off? It started last year. There have not been changes to our yard by this tree, it hasn't been under water, or had less water, etc. I have not observed any insects that are visible on the trunk, branches or leaves. It has been leafing out like normal.

Douglas County Minnesota trees and shrubs ash trees horticulture

1 Response

It looks like sunscald, which is caused by sudden cooling, usually in late winter. Thin-barked young trees, such as apple, maple and ash, are commonly affected. We recommend some kind of winter protection, such as a tree wrap, to reduce sudden temperature changes. Read here:
https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter#sunscald-1263860

Most likely the wound will heal. However, you can cut away dead tissue with a sharp knife. The damage to your tree is extensive, and the split might become a pathway for disease and insects. Unfortunately, there is nothing further you can do about it except to try to keep the tree healthy and to prevent future cracking by giving it winter protection.