To discourage black spot and other fungal diseases. Mix 1 tbs. Deterring powdery mildew Powdery mildew is a fungal infection that causes a white powdery surface to form on leaves, shoots and flower buds.
Some plants are more susceptible than others.
It is important to start the treatment early in the year if you have had problems with mildew previously. Remove and burn leaves and dead material from plants that have been affected to avoid spreading the spores. Start early in the year, just before the first buds open, and continue to spray every couple of weeks throughout the spring. Be alert and ready to spray between those times if you spot any signs of mildew on your plants.