This infamous condition is caused by a fungus that enters a tree’s vascular tissue, plugging it up and stopping the circulation of water and nutrients. Red Oaks are the most susceptible to this condition which is identified by sections of the tree’s canopy rapidly turning red or tan or a sudden shedding of foliage.

This fungus is largely spread by tiny sap-feeding beetles that are attracted to fresh wounds on the trees. If this condition is an issue in your area then it is recommended to avoid pruning Oak trees during the months that these beetles are most active (March, April, May and June).