Peeling and Splitting Bark on Shade Trees

Over the past several weeks, we’ve received reports (and photos) showing long strips of bark peeling away from the trunks of trees and other instances where bark appears to split or burst as if it were under pressure.

Peeling bark on Freeman maple (Acer ´freemanii). Photo courtesy of Terry Norris.

These symptoms are highly unusual and potentially harmful to the tree for many important reasons:

  • The bark is important for protecting trees (and their important water and food conducting tissues located just beneath the bark) from animals and mechanical injury.
  • The inner bark is involved in the transport of mineral elements and the products of photosynthesis.
  • Without bark, important regenerative tissues and water conducting elements that reside just below the bark could desiccate or suffer mechanical injury.

Possible causes/reasons for these symptoms are many but poorly understood, including:

  • Rapid fluctuations in either air temperature or soil moisture.
  • Extremes (high or low) in air temperature and/or soil moisture.
  • Squirrels or mechanical damage from careless human activity may cause similar symptoms, but evidence is usually available to either confirm or dismiss these factors.

Bark splitting on an elm (Ulmus spp.) Photo courtesy of Terry Norris. 

Treating exposed areas of wood with wound dressings or paints is not advised or recommended.  Similarly, taping or tacking bark pieces or strips back in place is rarely a successful repair strategy unless it can be done immediately after the injurious event occurs.  Proper and timely supplemental irrigation remains our best recourse and remedy for trees that have suffered injury to important bark and vascular tissues.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 18, 2021. The information contained within may not be the most current and accurate depending on when it is accessed.