Michigan State University Extension
Ornamental Plants plus Version 2.0 - 00001691
01/01/98
The leaf and stem blight of ground cover pachysandra caused by the fungus Volutella pachysandricola is a destructive disease that occurs throughout the north central United States.
Symptoms: Leaves show large, chocolate-colored blotches, then become withered and blighted. Stem tips are also affected. The stems shrivel and the infection generally spreads in blighted patches.
Cause: The fungus parasitizes plants under stress from drought, scale insects or winter injury, particularly when overcrowded beds and beds covered with damp fall leaves or heavy mulch retain humidity and extend the period of leaf wetness needed for infection by spores. Spores of the fungus form on the blighted leaves and stems and are splashed to other plants, where they cause new infections.
Control: Periodically thin out pachysandra beds, carefully remove severely infected plants, and prune out all blighted leaves and stems. For winter, use a mulch that does not hold water. In addition, control scale insects as recommended.