A number of cankers occur on vines and roses that cause dieback, including canker on rose and stem blight on clematis. These are more common on stressed plants in marginal sites or poorly maintained landscapes. Young cankers are slightly darker in color than adjacent healthy tissue and appear slightly sunken. As cankers enlarge they kill the living tissue within the branch or main stem. Canker growth may cause the tissue along the edges to crack and fall away, exposing the dead tissue underneath. After a canker enlarges enough to girdle a branch or trunk, the portion beyond the canker dies. Small twigs are killed more quickly than larger branches. Symptoms may include progressive upper branch dieback, disfigured branch growth, or target-shaped areas on main stems with concentric rings of dead tissue.
Prune out dead, diseased, or damaged canes or stems to the ground or into healthy tissue.