Oak Wilt

Oak wilt is a tree disease caused by the fungus Bretziella fagacearum. The fungus is widespread throughout the eastern United States and, as of 2021, found within 600 m of the Canadian border near Windsor, Ontario. The fungus clogs the vascular system of the tree, causing mortality within 1 year in red oaks, and in 2-15 years in white oaks. Infected trees also produce pressure pads where beetles can pick up fungal spores and move the fungus to new stands. Within stands, infections can also be transmitted by root grafting. This publication describes the biology, impact and management options for oak wilt.