Although too much water can injure the roots it is important that they receive adequate moisture, especially during the first year after transplanting. When they do occur it can often be traced back to their environment. Listed below are the two most common diseases of rhododendrons and azaleas. Not surprisingly then, this is one of the most common diseases to find in the first couple years after transplanting. This disease starts with the appearance of scattered dead branches among healthy branches.
Infection often begins at leaf scars, pruning wounds or dead flower clusters.
Leaves on affected branches will roll lengthwise or curl downward, turn brown and remain attached to the branches. Heat and drought stress in particular have been shown to lead to this disease. This disease will only develop where wet soil conditions occur. The leaves of infected plants look off-colored and eventually wilt. In the advanced stages the leaves are rolled lengthwise and the leaves and stems appear brown in color.