The most common disease of indoor roses is powdery mildew. To keep plants healthy, provide good air circulation near your plants, and water only in the morning. A homemade treatment for powdery mildew can be concocted from a solution of one part alcohol-based mouthwash and three parts plain water. Mix the two ingredients in a spray bottle, and apply to the leaves daily. Aphids, leafhoppers and other insects can be controlled with insecticidal soap or a systemic insecticide.
Insecticidal soap is nontoxic and easy on the plant.
It is safe to use indoors and around pets and children. Systemic insecticides work through the roots of the plant. Apply the product directly to the surface of the soil, and mix it in lightly. The chemical is absorbed by the roots and spreads throughout the plant. If you use systemics, apply once a month to prevent insect infestations.