Fungal Infection on rubber plant
What's Happening
Fungal infections in Ficus elastica typically manifest as secondary opportunistic pathogens (Cercospora, Myrothecium, Phyllosticta) invading tissue compromised by environmental stress. High humidity (>70%) combined with poor air circulation creates microclimates where fungal spores germinate on leaf surfaces. Overwatering-induced root rot often precedes foliar fungal issues by weakening the plant's systemic defenses.
How to Fix It
- 1
Identify fungal spots by irregular margins with yellow halos spreading across multiple leaves
- 2
Remove and dispose of infected leaves immediately; do not compost
- 3
Improve air circulation with small fan pointing near (not directly at) plant
- 4
Apply copper-based fungicide or neem oil spray to remaining foliage every 7-10 days
- 5
Check soil moisture—if wet >7 days, unpot and inspect for root rot contributing to systemic stress
How to Prevent It
Maintain 40-60% humidity with good airflow via fan or open windows. Avoid overhead watering that wets leaves. Quarantine new plants for 2-3 weeks. Water only when top 2-3 inches of soil are dry.