Oak wilt status: SAFE

UNIVERSITY OF MINNESOTA EXTENSION - www.extension.umn.edu

A young 'Majestic Skies'TM Northern pin oak (Quercus elipsoidalis)

What does it mean when we say “Oak wilt status is SAFE”?

Oak wilt is a debilitating fungal disease that can kill all species of oaks quickly. It spreads by sap beetle feeding and through diseased roots connecting underground with healthy roots.

Red oaks (Quercus rurbum, Q. ellipsoidalis) are more susceptible and killed more quickly by oak wilt than white oaks (Q. alba) and bur oaks (Q. macrocarpa).

When we talk about the safety status of oaks, we're referring to when it is safe to prune oaks without worrying about leaving trees vulnerable to oak wilt.

April to July is the most susceptible time for oak wilt to spread. July to October still has some level of risk, but less. This later risk level is somewhat weather-dependent.

According to Extension's forestry team, it is safe to prune oaks in Minnesota now through March when insect and fungal pathogens are inactive. Risk levels can vary considerably based on seasonal changes and location. Always check the oak wilt risk status for your date and location before pruning or wounding oaks.

Find out more about how you can prevent oak wilt in Minnesota.