Phytophthora Bleeding Canker of Maple Trees

Bleeding canker has recently been observed on mature maple trees in southern Idaho. The causal agent is Phytophthora cactorum, a plant pathogen capable of infecting over 200 tree species. Given its wide range, whose resultant root and crown rot can kill, it’s important to know how to identify and treat an afflicted tree. This bulletin discusses the symptoms and signs of an outbreak and its management. Full-color photography helps growers to identify potentially afflicted plants.