Oaks

Oaks are subject to infection by numerous pathogens, most of which do little more than temporary harm to the tree. The exceptions are root-related diseases caused by various fungi. Oak wilt, caused by Endoconidiphora fagacearum has become a serious problem in the eastern and central United States. Oak root rot or honey fungus (Armellaria spp.) and avocado root rot (Phytophthora spp.) are more problematic in the western region. Most oaks are resistant unless environmental stresses weaken the tree to the point that the fungus can proliferate. Little can be done to save a severely infected oak.