Hypoxylon canker, caused by Hypoxylon mammatum, is a fungal disease that, in our region, affects primarily trembling aspen, balsam poplar, and Swedish columnar aspen trees.

A patch of mottled orange and black bark marks the canker site.   This disease is usually fatal once the trunk is infected.

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

Close up of Hypoxylon Canker damage