Hypoxylon canker, caused by Hypoxylon mammatum, is a fungal disease that, in our region, affects primarily Trembling Aspen and Black Poplar trees.

A patch of mottled orange and black bark marks the canker sites. The pathogen may live on dead wood and is referred to as white rot. This disease is usually fatal once the trunk is infected.

Where possible try to reduce wounding to trunk or branches to eliminate infection sites. Prune out any affected wood and immediately dispose of it in a landfill or by burning.

Tree blighted with Hypoxylon Canker
Close up of Hypoxylon Canker damage