After roses have been pruned, lime sulfur may be sprayed on them as a winter spray. The concentration is 20 milliliters per liter of water, and it is sprayed over every area of the bush. Lime sulfur may also be used to control rust, two-spotted mites, and powdery mildew on roses throughout the Spring, Summer, and Autumn seasons; however, the rate that is needed to be applied is lower.