Low Light on calathea
What's Happening
Calathea require bright indirect light (100-300 μmol/m²/s or 200-400 foot-candles) for photosynthesis and nyctinastic movement. In low light (<100 μmol/m²/s), plants stretch toward light sources producing leggy, weak growth with small leaves. Insufficient light reduces transpiration, causing soil to stay wet longer and promoting root rot. Unlike true shade plants, Calathea cannot adapt to dark corners - leaf yellowing and drop indicate severe light deficiency.
How to Fix It
- 1
Move to brighter location with east or north-facing window
- 2
Use sheer curtains to filter direct sun
- 3
Supplement with LED grow lights 12-14 hours daily
- 4
Maintain 6-12 inches from window in winter when light is weaker
- 5
Rotate plant weekly for even light exposure
How to Prevent It
Position 3-6 feet from east or north windows. Avoid dark interior spaces. Use light meter app to verify 200+ foot-candles. Supplement with grow lights in winter months.