QuestionI have a philodendron that has a white, cotton-like substance in small spots on the leaves and stems. What is this and what can I do to fix it?
AnswerSounds like you are describing powdery mildew, a common fungal foliage disease of many plants. Go to your local garden supply store and purchase wettable sulfur powder. Mix this according to label instructions and treat once per week for about 3-4 applications. Move the plant outside to do this. Treat whenever you see the powdery mildew recur. If the sulfur is too much of a chemical for you, you can use the Cornell Fungicide which is composed of one tablespoon baking soda, one tablespoon vegetable oil and one gallon of water. The plant can be sprayed about every 3-4 days with this mix. Good luck.
