Answer: What you describe are classic symptoms of Botrytis gray mold. During cloudy weather and high humidity, the fungus occurs on soft, succulent plant material, building up rapidly on tender flower petals, buds and new shoots. Cultural control measures include reducing humidity and increasing air circulation around the plant, and removing infected plant parts to stop the spread of the disease. You can use a fungicide to prevent botrytis, but increasing space between your plants will help your dahlias avoid the problem in the first place. Now, if we could only control the weather!
Q&A Library Searching Tips