Is it possible to control downy mildew on impatiens?
In landscape plantings, control of downy mildew on impatiens with fungicides is not practical. Sanitation is the best management strategy for this disease. Remove and destroy infected plants as soon as they are noticed to reduce the spread to healthy plants and minimize the amount of over-wintering inoculum (oospores). Do not place infected plant material in home compost piles. Temperatures in home compost piles often don’t get high enough to kill disease pathogens. Avoid planting common garden impatiens in areas that experienced a downy mildew problem the previous year. Plant shade tolerant alternatives, such wax begonias, pansies, lobelia, torenia, caladium, and coleus.