Summer is drawing to a close and fall is near. The oaks are getting ready to put on their fall show and go into dormancy for the winter. As tree stewards we may think that it is time to put on our winter weight and go into hibernation ourselves. However, winter is a great time to care for oaks. We can help by pruning them and removing invasive trees like buckthorn and honeysuckle that grow beneath their canopies.
Trimming oaks in the winter months helps prevent diseases like oak wilt and insects like the two-lined chestnut borer. We recommend waiting until after frost to prune and completing pruning activities by April 1. The additional benefit of trimming this time of year is that gardens are dormant so the risk of damaging nice plants under the canopy of oaks is lessened by trimming while the garden sleeps.
Some people ask if you can tell the dead branches in the winter months, and the answer is yes—an experienced tree pruner can identify dead limbs even without leaves by looking for next year’s buds and examining the bark of the limb to be cut.
Winter is also a great time to remove woody invasives. If equipment is going to be used there is less disturbance to the root zone of the oaks if the weed trees are removed when the ground is frozen. It is also easier to see and work in oak woods when there are no leaves on the trees (and no mosquitoes).
Just because winter is on the way does not mean we should stop caring for oak trees. Some of the best things that can be done to help oak trees can be done after the snow flies.