In rainy weather when things haven't had much chance to dry out, groundcover beds can take a hit from fungal diseases. Some pachysandra beds have been infected by a disease called Volutella, which causes brown leaf blotches and stem cankers. Vinca beds have been infected by Phomopsis, causing the shoot tips to wilt, turn brown, and die back to the soil surface. Affected stems may turn black. In both cases, plants may die out in patches, leaving gaping holes in the groundcover planting.