low light and Calathea
Quick answer
If low light is what's going on with your Calathea, the most likely cause is: 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.
Start here:
- 1. Move to brighter location with east or north-facing window
- 2. Use sheer curtains to filter direct sun
Why low light happens to Calathea
Goeppertia spp.
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 correct low light on Calathea
- 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
Keep low light from repeating on this Calathea
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.