Inspect rose gardens regularly.
Make finding the troublemakers a priority. Learn to identify the most common infestations (aphids, whiteflies, spider mites, fungus and mildew).
Cut away all infected areas.
Create an anti-fungal/anti-mildew spray by adding 1 tbsp. baking soda and 2 1/2 tbsp. vegetable oil to 1 gallon water.
Cover the remaining plant surfaces with the solution, using either a spray bottle or a garden hose attachment.
Repeat every two weeks or as symptoms appear.
Mix 1 c. vegetable oil with 1 tbsp. liquid dishwashing soap. Add 1 1/2 tsp. of this mixture per 1 c. warm water. Pour the solution into a handheld spray bottle.
Hit each infestation directly.
Spray the plant thoroughly.
Repeat weekly or as needed.
Introduce ladybugs to your garden. They will happily munch aphids and other soft-bodied insects until they fly away home.