Question: The new growth on my otherwise healthy phlox wilts and curls. How can I control this?
Answer: The problem sounds like powdery mildew, a common fungal disease of numerous ornamental plants, including dogwood, rose, phlox, and many bedding plants. It thrives in humid or damp weather and moderate temperatures. Increasing air circulation and light penetration can reduce the infection, or you can try one of the fungicides available at garden centers.