Identification

• Gray mold is also known as botrytis blight. This fungus is spread from flower to flower by spores carried on the wind or in water. Gray mold can attack dahlias during any part of the growing season.
  
  

Symptoms

• Dahlia bulbs infected with gray mold develop symptoms such as browning of buds and flowers, flecks in flower bulbs and brown spots on flowers and leaves. Cool, damp weather conditions favor the development of gray mold.
  
  

Control

• Cultural control practices such as good sanitation are key to controlling gray mold in your dahlias. Remove and destroy any plants or plant parts that show signs of infection to prevent the spread of disease. Avoid placing dahlias too close together; overcrowded damp areas breed fungus. Do not use overhead watering systems, as this promotes fungal diseases. Water your dahlias early in the day, so they dry completely.