Perennial Canker (Bull's-eye Rot)

Unlike anthracnose cankers that grow one season then stop expanding, these cankers enlarge year after year, gradually girdling limbs and causing eventual death. Cankers are very difficult to remove once established due to their persistent expanding nature. Prune well below visible symptoms and destroy all infected material promptly to prevent spread.

Reduce moisture around affected tissue by improving drainage and air circulation. Remove rotted material cleanly and dispose of it away from the planting area. Avoid wounding healthy tissue during cleanup, as fresh wounds create new entry points. If the problem keeps returning, evaluate whether the site is too wet or poorly drained for the species you are growing.