Calathea moisture requirements
Quick answer
For Calathea, moisture requirements come down to this: Calatheas are highly sensitive to soluble salts, fluoride, and chlorine in tap water. These chemicals accumulate in the leaf margins (tips) during transpiration, leading to osmotic stress and localized cell death. This results in the characteristic 'rusty' or brown crispy tips seen even when humidity is ostensibly adequate. PMIDs: 27354737, 29494547.
Start here:
- 1. 1. Flush the soil thoroughly with 3x the pot's volume of distilled water to remove mineral buildup.
- 2. 2. Switch to a zero-TDS or low-mineral water source immediately.
What moisture requirements mean for Calathea
Goeppertia spp.
Calatheas are highly sensitive to soluble salts, fluoride, and chlorine in tap water. These chemicals accumulate in the leaf margins (tips) during transpiration, leading to osmotic stress and localized cell death. This results in the characteristic 'rusty' or brown crispy tips seen even when humidity is ostensibly adequate. PMIDs: 27354737, 29494547.
How to meet Calathea moisture requirements
- 1
1. Flush the soil thoroughly with 3x the pot's volume of distilled water to remove mineral buildup.
- 2
2. Switch to a zero-TDS or low-mineral water source immediately.
- 3
3. Pause fertilization for 4 weeks to allow the plant to recover from osmotic shock.
Keeping Calathea in range
Exclusively use distilled, rainwater, or reverse osmosis water. If using tap water, let it sit for 24-48 hours to off-gas chlorine (note: this does not remove fluoride). Flush soil monthly with pure water to leach accumulated salts.