Prevention is always easier than cure. All rose gardeners in all growing zones want to prevent growing problems in future seasons. The fungus spores I discussed yesterday will winter over if allowed to remain on the plant or on the ground. Cold and freezing conditions do not destroy these fungi. Removing all petals and leaves, diseased or not, should be goal in a well maintained rose garden. If you see disease, do not put them in your home compost because you most likely will spread the disease spores in the compost! Some roses naturally shatter petals, such as below.