High Humidity? (Low VPD Stress)
Too high RH slows transpiration; leaves droop, risk mold.
High humidity stress? Low VPD, droop, mold risk—see fixes and analyze fast.
Common Causes
- RH above target for stage
- Weak exhaust/airflow
- Dense canopy trapping moisture
How to Tell Which One You Have
Droop with soft leaves, little dryback; VPD chart shows low; risk of PM/Botrytis.
FAQ
Fix?
Increase exhaust/airflow or dehumidify to target VPD.
Defoliate?
Light selective defol to improve airflow.
Does this cause tip burn?
Less; main risk is mold and slow uptake.
Browse problem guides
- White Tops? (Light Bleaching)
- Stretching Seedlings? (Light Too Weak)
- Fluffy/Larfy Buds? (Low Light/Heat/Overfeed)
- Light Leaks in Flower? (Re-Veg/Herm Risk)
- Cold Stress on Cannabis? (Low Temperature Damage)
- Cold Temperature Stress Cannabis
- Wind Burn on Cannabis? (Fan Damage)
- Temperature Fluctuations? (Temp Swings)