Environment & care
Low humidity
Crisp brown edges, curling leaves and buds that drop when the air is drier than the plant evolved for.
What you'd see
- Brown, crisp leaf edges and tips without a salt crust
- Leaves curling inward or new leaves tearing as they unfurl
- Flower buds dropping before opening
- Worse in winter when heating is on
Where to look
Heated rooms in winter (often 20–30% relative humidity), near radiators and vents, air-conditioned rooms in summer.
How it spreads
Not infectious.
Is it really this? Look-alikes
- Fertiliser burn — Salt burn comes with a crust and a yellow band; humidity burn is clean crisping.
- Underwatering — Thirst crisps whole leaves and the pot is light; low humidity crisps edges on well-watered plants.
What's going on
Leaves lose water through pores. The drier the air, the faster it leaves — faster than roots can replace it at the leaf's thin edges, which die first. Calathea, ferns and many aroids evolved in 70–90% humidity.
Why?
The 'vapour pressure deficit' — the gap between what the air holds and what it could hold — is what drives water out of the leaf. Warm dry air has a huge deficit. Raising humidity or lowering temperature both shrink it, which is why grouping plants in a cooler room works.
Grandmother's remedies
What people have always done — with an honest note on each.
Group the plants
Cluster humidity-lovers together; they humidify each other.
Verdict: Measurably raises local humidity a few percent. Helpful.
Pebble tray
Pot on pebbles above a tray of water.
Verdict: Small local effect; better than nothing, less than a humidifier.
Misting
Spraying leaves with water.
Verdict: Raises humidity for minutes only and encourages leaf spot. Mostly a ritual.
The bathroom
Move ferns and calathea to a bright bathroom.
Verdict: Often the best spot in the house.
Modern remedies
What growers and extension services reach for today.
A humidifier with a hygrometer
Aim for 45–60% in the plant area; measure, do not guess.
Verdict: The one intervention that actually moves the number.
A closed cabinet or terrarium
For the genuinely demanding species.
Verdict: Highly effective for small plants.
Honest verdict
Most common houseplants (pothos, snake plant, monstera) tolerate ordinary room humidity. Buy a hygrometer before buying remedies, and choose plants for the air you have.
Prevention
- Measure humidity in winter
- Keep plants away from radiators and vents
- Choose tolerant species for dry rooms
Plants this commonly troubles
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