Humidity on calathea
What's Happening
Calathea species evolved in tropical understory environments with 70-90% relative humidity year-round. Their thin leaf tissue and specialized stomata require high ambient moisture to maintain turgor pressure and prevent excessive transpiration. When humidity drops below 60%, physiological stress triggers: (1) stomatal closure reducing CO2 intake, (2) nyctinastic movement cessation (failure to 'pray'), and (3) marginal leaf necrosis. Unlike succulents that store water, Calatheas rely entirely on environmental humidity and consistent soil moisture.
How to Fix It
- 1
Maintain 60-80% RH using cool-mist humidifiers - warm mist can burn leaves
- 2
Group with other tropicals to create transpiration microclimate
- 3
Use pebble trays with water level below pot bottom
- 4
Place in bathroom with adequate indirect light for passive humidity
- 5
Avoid heating vents and air conditioning which reduce humidity to 30-40%
How to Prevent It
Install digital hygrometer near plant. Calibrate watering to humidity levels - higher humidity allows slightly less frequent watering. Maintain consistent humidity year-round, not just winter.