Gray Mold (Botrytis): Identification, Control & Prevention

Gray mold (Botrytis cinerea) is a ubiquitous fungus attacking damaged or dying plant tissue, then spreading rapidly to healthy parts. It's one of the most common diseases in bedding plants. Moisture and plant injury are the primary triggers.

Identification

• Water-soaked spots on leaves, initially white, turning gray to brown.
• Leaf wilting and browning (often confused with brown mold).
• Under high humidity: grayish webbing with fuzzy spore structures.
• Petals, stems, and buds also infected.
• Eventually, a fuzzy gray growth covers infected areas.

Control

• Remove and destroy infected plants immediately.
• Clean thoroughly between plants to prevent spread.
• Cultural sprays may limit further infection.

Prevention

• Handle plants carefully during transplanting/pruning—wounds invite infection.
• Keep foliage dry: avoid overhead watering and late-day watering.
• Space plants for good air circulation.
• Remove all debris: cuttings, dead leaves, spent flowers.