If your calathea or prayer plant has gone crisp at the edges since the heating came on, you're in good company. These are tropical plants that need high humidity. A centrally heated British living room in January is about as far from that as a room can get. The edges that have already browned won't recover. You can stop it spreading, though, and most of the fix is about where the plant sits.
01At a glance
- Crispy brown edges and tips: low humidity is the usual cause, says the RHS. Hard tap water and too much feed can add to it.
- Leaves curling or rolling in the day: usually thirst. Heat stress or a cold draught are the next suspects.
- Leaves folding up at night: completely normal. It's called nyctinasty, and it's how the prayer plant got its name.
- Fix the room before the plant: away from radiators, out of draughts, ideally in a bright bathroom or kitchen.
02First, a name change
The RHS notes that many plants sold as calathea have been moved into three other genera: Goeppertia, Ctenanthe and Stromanthe. Our calathea profile files it under Goeppertia, though shop labels are slow to catch up. The prayer plant is a close cousin, Maranta leuconeura. Both want the same things, and both show stress in the same way.
03Crispy edges: what to do
- Move it away from heat. The RHS tells calathea owners to keep them away from radiators and fires, and notes that dry air is most common in winter when the heating is on. A pot on the sill above a radiator will crisp, whatever else you do.
- Find it a more humid room. The RHS says kitchens and bathrooms generally have higher humidity than other rooms. A bright bathroom with a frosted window suits a calathea well.
- Group it with other plants. The RHS and Iowa State University's extension service both suggest this, as clustered plants share the moisture they give off. How much it helps depends on how many plants and how big the room is, notes Penn State Extension.
- Think about a humidifier if you've several fussy plants. Iowa State calls humidifiers an excellent way to raise indoor humidity.
- Switch to rainwater. The RHS recommends rainwater for calatheas, or tap water left to stand for at least 24 hours. NC State Extension warns that prayer plant leaves burn with high fluoride and too much fertiliser.
- Trim the damage. Snip off brown edges with clean scissors, following the leaf's outline and leaving a sliver of brown so you don't cut into live tissue. Remove leaves that are completely brown. The RHS says these won't recover.
### What about pebble trays and misting?
Here the experts genuinely disagree, so we'll be straight with you. The RHS suggests a tray of damp gravel and regular misting for calatheas. Penn State Extension says moisture from a pebble tray spreads into the whole room and makes almost no difference, and that even daily misting does nothing for humidity around the plant. Iowa State says foliage dries quickly after misting, so you'd have to mist several times a day for it to work.
A pebble tray is cheap and does no harm, as long as the pot sits above the water line. Just don't expect misting to rescue a plant that's sitting over a radiator.
04Curling leaves: is it thirst, heat or cold?
Before you diagnose anything, check the time of day. Prayer plant and calathea leaves lift and fold together in the evening and open again in the morning. NC State describes prayer plant leaves held flat by day and upright "in prayer" at night. That's a healthy plant, not a curling one.
Leaves that stay curled or rolled during the day are another matter:
- Compost dry a couple of centimetres down? It's thirsty. Both plants like evenly moist compost in growth. In autumn and winter, the RHS lets the surface dry before watering again, but never lets the compost dry out completely.
- Compost moist, plant in strong sun or near a heater? The RHS links leaves rolling, bleaching and going crispy to heat stress. Move it to bright, indirect light. Direct sun also fades the markings.
- Near a door or a cold window at night? NC State says the prayer plant won't tolerate low temperatures or cold draughts, and the RHS links draughts to yellowing and dry leaf edges. Keep both plants in steady warmth, never below about 16°C.
05Mistakes that make it worse
- Overwatering to compensate. Crispy edges aren't thirst. The RHS warns that compost that's too wet in winter can cause oedema, which shows as patchy, water-soaked areas on the leaves.
- Feeding in winter. The RHS feeds calatheas monthly from April to September only.
How we checked this
Every care and safety claim on this page is verified against horticultural and veterinary sources.
Sources: RHS — Calathea: growing guide · RHS — How to help a poorly houseplant · NC State Extension — Maranta leuconeura · Penn State Extension — Humidity and houseplants · Iowa State University Extension — Should I mist my houseplants in winter?
Checked 8 October 2026. If our advice ever conflicts with the RHS, believe them and tell us.