Root Rot on calathea orbifolia
What's Happening
Calathea orbifolia root rot develops when the fine, fibrous root system remains in waterlogged, anaerobic soil for 5-7+ days. Unlike drought-tolerant plants, Calatheas lack water storage tissues and require consistent moisture—but not saturation. When soil remains saturated below the surface, oxygen levels drop below 2mg/L, triggering anaerobic bacterial proliferation (Pythium, Phytophthora) that breaks down root cortex cells. Early warning signs include subtle yellowing of newest leaves first (indicating vascular uptake failure), softening leaf texture, and fungus gnat presence.
How to Fix It
- 1
Unpot immediately: Gently remove plant from soil, shake off medium, rinse roots in lukewarm water
- 2
Inspect and trim: Cut away all black, mushy, or foul-smelling roots with sterilized scissors until only white/firm tissue remains
- 3
Sterilize remaining roots: Soak in 3% hydrogen peroxide solution (1:1 with water) for 15 minutes to oxygenate and kill pathogens
- 4
Allow callus formation: Lay plant on dry paper towel in shade for 48 hours to seal cut wounds
- 5
Repot in fresh dry mix: Use new well-draining aroid mix; do not water for 5-7 days post-repot
- 6
Resume minimal watering: After 1 week, water sparingly until new growth indicates recovery (typically 3-5 weeks)
How to Prevent It
Use well-draining aroid mix: 40% peat/coco coir, 30% perlite, 20% orchid bark, 10% charcoal. Ensure pot has 4-6 drainage holes minimum. Water only when top 2 inches of soil are dry to touch—use finger test or moisture meter. Elevate pot on feet to allow drainage and airflow beneath. Avoid decorative cache pots that trap water.