Crown Rot on african violet
What's Happening
Crown rot in African violets is primarily caused by Dickeya chrysanthemi (formerly Erwinia chrysanthemi), a bacterial pathogen that thrives in waterlogged, anaerobic soil conditions. The bacteria enter through wounds or natural openings and produce pectolytic enzymes that break down plant cell walls, causing characteristic soft, mushy decay at the crown where leaves emerge. Unlike fungal root rot (which affects roots first), bacterial crown rot attacks the central growing point, emitting a distinct foul/sour odor. The pathogen spreads rapidly in warm (75-85°F), humid conditions with poor air circulation.
How to Fix It
- 1
Immediate isolation: Remove infected plant from collection to prevent spread via splashing water
- 2
Surgical removal: Trim ALL affected tissue with sterile scissors until only firm, healthy white tissue remains
- 3
Sterilization: Treat cut surfaces with cinnamon powder or diluted hydrogen peroxide (1:4 ratio) to prevent reinfection
- 4
Repot in fresh sterile mix: Use new African violet potting soil with 30% perlite; never reuse contaminated soil
- 5
Bottom-water only: Prevent future crown wetting; use room-temperature filtered water
- 6
Withhold fertilizer for 4-6 weeks to reduce stress on compromised tissue
How to Prevent It
Avoid overhead watering—water droplets on fuzzy leaves funnel bacteria into the crown. Ensure pot has drainage holes; never let plant sit in standing water. Maintain 50-60% humidity with good air circulation. Quarantine new plants for 2 weeks. Use room-temperature water—cold water causes cell damage that invites infection.