crown rot on African Violet
Quick answer
If your African Violet has crown rot, the most likely cause is: Erwinia chrysanthemi bacteria invades through wounds or natural openings, producing pectin methylesterase (PME) and pectate lyases that break down plant cell walls. The pathogen requires iron-regulated outer membrane polypeptides (80-90 kDa) and flavohaemoglobin HmpX for full virulence under low oxygen conditions, causing soft-rot symptoms at the crown where humidity accumulates.
Start here:
- 1. Unpot immediately and inspect roots - trim all mushy black roots with sterile scissors until white healthy tissue appears
- 2. Rinse roots under lukewarm water and dust cut surfaces with cinnamon powder as antifungal barrier
Why African Violet gets crown rot
Erwinia chrysanthemi bacteria invades through wounds or natural openings, producing pectin methylesterase (PME) and pectate lyases that break down plant cell walls. The pathogen requires iron-regulated outer membrane polypeptides (80-90 kDa) and flavohaemoglobin HmpX for full virulence under low oxygen conditions, causing soft-rot symptoms at the crown where humidity accumulates.
Other documented causes on african violet:
- • 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 reverse crown rot on African Violet
- 1
Unpot immediately and inspect roots - trim all mushy black roots with sterile scissors until white healthy tissue appears
- 2
Rinse roots under lukewarm water and dust cut surfaces with cinnamon powder as antifungal barrier
- 3
Repot in fresh sterile African violet mix at original depth - crown should sit at soil surface never buried
- 4
Place in sealed clear humidity dome for 1-2 weeks maintaining 80-90% humidity to reduce transplant shock
- 5
Withhold water for 3-5 days after repotting, then resume bottom-watering sparingly with room-temperature filtered water
Keep crown rot off this African Violet
Use well-draining African violet mix (peat/perlite/vermiculite), bottom-water only when top 1 inch is dry, maintain 50-60% humidity with pebble trays not misting, and avoid getting water on the crown or fuzzy leaves.