Fungal Infection on orchid
What's Happening
Fungal infections in orchids typically develop when prolonged leaf wetness combines with poor air circulation and warm temperatures. Common pathogens include Botrytis (gray mold), Colletotrichum (anthracnose), and various leaf spot fungi. The epiphytic nature of orchids makes them particularly susceptible as their thin leaves lack the thick cuticle of terrestrial plants. Infections often start at wounds or stressed tissue, spreading rapidly in crowded, humid growing conditions.
How to Fix It
- 1
Remove severely infected leaves with sterile scissors, cutting well below visible symptoms
- 2
Apply fungicide containing chlorothalonil or copper-based compounds to remaining foliage
- 3
Improve air circulation immediately with fans to reduce humidity around plants
- 4
Water early morning only, ensuring leaves dry completely before evening
- 5
Reduce humidity temporarily to 40-50% during treatment to slow fungal spread
- 6
Disinfect all tools between plants with 70% alcohol or bleach solution
How to Prevent It
Maintain 50-70% humidity with constant gentle airflow; water at soil level avoiding leaf wetness; space orchids adequately to ensure air movement; quarantine new plants for 2-4 weeks; remove spent flowers and damaged tissue promptly; sterilize cutting tools between plants