Botrytis Gray Mold 🦠

Moderate Disease also: gray mold, botrytis blight, bud rot, Botrytis / Gray Mold

Affects these houseplants: African Violet

At a glance

  • Cause: Fungal disease favored by cool, damp, stagnant conditions
  • Tell-tale sign: Gray fuzzy mold on dying flowers, buds, leaves, or soft stems
  • Severity: Moderate — can spread quickly in crowded, humid plantings

How to identify

Botrytis usually starts on old flowers, damaged tissue, crowded leaves, or soft new growth. Look for tan-brown collapse followed by gray, fuzzy spores, especially after cool damp weather or in humid indoor conditions.

What causes it

Botrytis spores are common and infect vulnerable tissue when humidity is high, airflow is poor, and plant surfaces stay damp.

Treatment & management

Following Integrated Pest Management:

  1. Remove infected flowers and leaves immediately; bag them instead of composting indoors.
  2. Increase airflow and spacing around crowded plants.
  3. Avoid wetting flowers and foliage, especially late in the day.
  4. Clean tools and benches if working with houseplants or propagation trays.
  5. Fungicides are prevention, not resurrection — they rarely fix tissue already rotting.

Prevention

Deadhead promptly, remove dying leaves, reduce humidity pockets, and keep propagation setups clean.

Affects (in this guide)

Flowers, propagation trays, crowded houseplants, greenhouse plants, and damp outdoor ornamentals

Sources