Infections appear on current-year stems at bud sites or wounded areas as small reddish brown areas in early spring. As these cankers enlarge, centers usually become gray and margins are reddish brown or dark brown, giving the canker a bull's-eye appearance. Small, dark pimple-like pycnidia can frequently be found in the canker. Cankers become progressively larger each year and eventually may girdle stems, causing them to wilt and die. Leaves on infected branches may turn color earlier in the fall.