Prevent oak wilt by waiting to prune oaks

Jan Byrne<byrnejm@msu.edu>, MSU Diagnostic Services, Department of Plant Pathology -

To minimize oak wilt infection risk, wait until November to prune oaks.

Oak wilt, caused by a fungal pathogen, Ceratocystis fagacearum, is present in Michigan. Impacts of this disease can be devastating, causing rather rapid death of large oak trees in landscapes and natural areas. One of the most effective ways to prevent infection of healthy trees is proper timing of any oak pruning. The months of April, May, and June are considered the months with the highest risk for above ground oak wilt infection. As a result, oaks should not be pruned at this time.

The months of November to March are the safest time to prune oaks, when there is no to extremely little risk of oak wilt infection.

For more information on pruning and associated oak wilt risks, visit the following University of Minnesota websites:

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).

Did you find this article useful?

You Might Also Be Interested In

Tag List
  • forestry,
  • landscaping,
  • lawn & garden,
  • msu extension,
  • natural resources
Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).