Tree Pruning & Oak Wilt Prevention: TFS/ISAT Official Recommendation

This post is from 2011. More recently, the recommendation has been to "avoid wounding" between February and June, and unfortunately most people would interpret this to mean don't prune during the period. The official recommendation issued in January 2011 exists to address some specific pruning implications, and the most important part of it, in my opinion, addresses the fact that sometimes pruning actually reduces wounding and the risk of oak wilt infection.

Guidelines and recommendations for pruning practices pertaining to oak wilt prevention have changed several times since the early '80's. The original suggestion was to prune only in January and August, our most extreme temperature months. More recently, the recommendation has been to avoid wounding between February and June. In January 2011 the Texas Forest Service, Texas AgriLife Extension Service and the International Society of Arboriculture Texas Chapter met to develop the guidelines for oak pruning to help prevent the above ground spread of oak wilt.

The cliche example would be pruning back low hanging limbs in a street. A limb that is struck by passing trucks gets re-wounded on a daily basis, and that persistently exposed wound is more of a risk than a single pruning cut that will heal quickly.

This scenario commonly crops up quickly when spring growth flushes come out and weigh down branches. That is when a low hanging limb over a street starts getting struck by passing trucks and re-wounded on a daily basis.