Problem: Crown Rot (Hosta)
This plant disease, also known as Southern blight, is caused by a fungus (Sclerotium rolfsii) that lives in the soil. The fungus is widespread in the South and attacks many types of plants. It spreads by moving water, diseased transplants, infected soil, and contaminated tools, traveling short distances over the soil to attack adjacent plants. The fungus produces tiny ''mustard-seed'' pellets, called sclerotia; these are white when young, maturing to dark red or brown. Sclerotia survive many years in soil, infecting healthy plants when conditions are suitable, especially in hot, humid weather. In the early 1990s, the disease appeared on hostas in the upper Midwest, perhaps coming from southern-grown plants. It survives cold winters.
Infected plants cannot be cured. Remove and discard infected plants and don''t transfer soil or plants to other parts of the garden. If possible, also remove the infected soil to a depth of 8 inches. Replant with resistant plants. Clean tools, shoes, and wheels thoroughly. Keep the soil immediately around plants in the diseased area free of mulch and plant debris.