Unfortunately, tree wrap, when left on in the spring and summer, can provide a habitat for disease organisms. If tree wrap is to be used on a newly planted tree for winter protection, be sure to remove the following spring. Cankers caused by herbicide injury . These herbicides may be absorbed through the bark of young, thin-barked species that still have green, yellow, or red pigment in the bark. Tree trunks will not exhibit herbicide injury for a year or two after application.
Glyphosate injury appears as a slit in the bark.
Depending on the amount of herbicide intercepted by the bark and species sensitivity, the split may extend a few inches or few yards. Glyphosate injury may be confused with frost cracks, however, cracks associated with herbicide injury may occur on any side of the tree. Other causes of bark injury and cankers . The injury from some insect pests may mimic canker diseases. The bronze birch borer feeds on cambium tissue, which causes a sunken canker on the bark.