External Factors
Dry air (low humidity)
Ambient humidity that is too low for tropical plants.
Many houseplants from tropical regions suffer when the air is too dry, especially where homes are heated during winter. Low humidity dries and browns leaf tips and edges, starting with sensitive plants such as calatheas, ferns, palms, and spider plants.
Signs to check
- Brown, dry leaf tips and edges.
- Sensitive plants: calatheas, ferns, palms, and spider plants.
- Dry air, often near a radiator or during a heated winter, with humidity below 40%.
What you may notice
- Brown leaf tips · Leaf tips turn brown, dry, and brittle, with a clear boundary between healthy and affected tissue.
- Dry, brown leaf edges · Brown, brittle drying appears along leaf edges or tips and spreads toward the center of the blade.
What to do now
Increase humidity
- Move the plant away from dry heat sources: radiators, heating vents, and fireplaces.
- Group plants together or place the pot on a tray of clay pebbles kept moist, without letting the pot stand in water.
- For the most demanding species, use a humidifier to aim for 50 to 60% relative humidity.
- Neatly trim tips that are already dry. They will not turn green again, but the plant will produce healthy new foliage.
Prevention
- Monitor a hygrometer during winter heating where it is used.
- Avoid excessive misting, which encourages leaf spots and disease.