Problem: Anthracnose (Hosta)
This leaf-spot disease is caused by a fungus (Colletotrichum) that is most active in warm, wet weather. The fungus spends the winter in dead plant tissue. It spreads new spores in the spring. Leaves must be wet for an extended period before infection can take place.
Remove and dispose of the infected leaves. Avoid overhead irrigation in the evening when leaves will stay wet for hours. In the fall, remove and dispose of all dead leaves to prevent the disease from returning next year. When planting hosta, space plants far enough apart for good air circulation and quick drying.