Pruning of oak trees is best done in the winter months between November and April. This will help to prevent the dreaded oak wilt disease, a systemic problem that is very difficult to stop once it has taken hold. Oak wilt occurs when the tree is most vulnerable in its growth season.

Do oak trees need to be pruned?

Pruning: • It is best to prune oaks when they are dormant. Live oaks, which retain their leaves year round, are dormant July thru October. Deciduous oaks, which lose their leaves in winter, should be pruned during the winter. Oaks do not tolerate severe pruning and can be killed if topped or severely pruned.

When should you not trim an oak tree?

Oak wilt is most active from April to July, which is why you should never trim oak trees in the summer. To be safe, you should avoid pruning between April 1 and October 1. Davey arborists recommend pruning oak trees between November 1 and March 31.