Quick diagnosis
Symptom: Your calathea’s leaves are curling inward along the edges, sometimes with brown crispy margins.
Most likely cause: Low humidity or underwatering. Calatheas curl their leaves to reduce moisture loss when the air is dry or the soil is parched.
Your 60-second first step: Feel the soil and glance at the room. Dry soil? Water now. Dry air or a nearby heater? Boost humidity. Sitting in direct sun or a cold draft? Move it to gentle, indirect light.
Calatheas are the supermodels of the houseplant world — stunning patterned leaves that also happen to be incredibly fussy. Leaf curling is their signature complaint, and it almost always means the plant is trying to conserve moisture. The good news: curling leaves are a warning, not a death sentence. This guide explains why are my calathea leaves curling, with seven causes and the exact fix for each. For general leaf-trouble triage, see our symptom hub and the Plant Emergencies archive.
1. Low humidity (the #1 cause)
Why it happens: Calatheas evolved in humid rainforests. When indoor air drops below 50% humidity — common with heating or AC — the leaves lose water faster than roots can replace it, so they curl inward to reduce surface area.
How to confirm: Leaf edges curl and turn brown and crispy, the air feels dry, and the plant sits near a heater, AC vent, or in a dry room. A hygrometer reading under 50% confirms it.
Fix it:
- Run a humidifier nearby — aim for 60% humidity or higher for calatheas.
- Group plants together to create a humid microclimate.
- Move away from heaters and drafts.
- Already-curled leaves may not fully uncurl, but new growth will emerge flat and healthy.
2. Underwatering
Why it happens: Calatheas like consistently moist (not soggy) soil. When the soil dries out completely, the plant curls its leaves to slow water loss — the same conservation strategy as with low humidity.
How to confirm: The soil feels dry 2 inches down, the pot feels light, and curling improves noticeably after watering.
Fix it:
- Water thoroughly until it drains from the bottom.
- Going forward, water when the top inch feels dry — don’t let it go bone-dry.
- Consider a self-watering pot if you tend to forget.
3. Too much direct light
Why it happens: Calatheas are understory plants that burn in direct sun. Harsh light stresses the leaves, causing them to curl, fade, and develop crispy brown patches.
How to confirm: The plant sits in a south or west window with direct sun, leaves look washed-out or have bleached spots, and curling is worst on the sun-facing side.
Fix it:
- Move to bright, indirect light — an east or north window, or back from a sunny one.
- A sheer curtain filters harsh rays effectively.
- New leaves will emerge with proper color and flat shape.
4. Temperature stress: cold drafts and heat
Why it happens: Calatheas are tropical and sensitive to temperature swings. Cold drafts from windows or doors, or hot blasts from heaters, cause leaves to curl as a stress response.
How to confirm: Curling started after a weather change, or the plant sits near a drafty window, exterior door, or heating vent.
Fix it:
- Move to a spot with stable temperatures between 65 and 80°F (18–27°C).
- Keep away from cold windows in winter and heat sources year-round.
- Damaged leaves won’t uncurl, but the plant will produce healthy new ones.
5. Overwatering and root problems
Why it happens: Soggy soil suffocates calathea roots, and damaged roots can’t deliver water — so the leaves curl from thirst even in wet soil. If you’re unsure which watering problem you have, see our overwatered vs underwatered guide.
How to confirm: Soil stays wet for days, the pot feels heavy, and lower leaves may yellow. The plant doesn’t improve after watering.
Fix it:
- Let the soil dry out and ensure the pot drains freely.
- If severe, unpot and trim black, mushy roots.
- Repot in fresh, airy mix if the old soil smells bad.
6. Tap water chemicals
Why it happens: Calatheas are famously sensitive to fluoride, chlorine, and mineral salts in tap water. These build up in the soil and leaf tips, causing curling, browning edges, and crispy margins even when everything else is right.
How to confirm: Leaf edges brown and curl despite good humidity and watering, and you water straight from the tap. White crust on the soil surface is another clue.
Fix it:
- Switch to filtered, distilled, or rainwater for your calathea.
- If using tap, let it sit out 24 hours (this helps chlorine, though not fluoride).
- Flush the soil occasionally with clean water to wash out mineral buildup.
7. Spider mites or other pests
Why it happens: Spider mites love dry conditions and calatheas. They suck sap from leaves, causing stippling, curling, and fine webbing — often mistaken for a humidity problem.
How to confirm: Look closely under leaves for tiny moving dots and fine silk webbing. Leaves may have a dusty, speckled appearance.
Fix it:
- Wipe leaves with a damp cloth and shower the plant to dislodge mites.
- Apply insecticidal soap or neem oil, repeating weekly for 3 weeks.
- Raise humidity — mites hate moist air, and your calathea will thank you twice.
Calathea curling: quick differential
| What you see | Likely cause | Instant check |
|---|---|---|
| Curling + crispy brown edges, dry air | Low humidity | Hygrometer below 50% |
| Curling improves after watering | Underwatering | Dry soil 2 inches down |
| Curling on sun-facing side, faded color | Too much light | Direct sun exposure |
| Curling + brown edges despite good care | Tap water chemicals | White crust on soil |
| Curling + fine webbing under leaves | Spider mites | Magnifying check undersides |
| Curling + yellow leaves, wet soil | Overwatering | Soggy soil for days |
How long until it recovers
Badly curled leaves rarely flatten completely — think of curling as the plant’s permanent record of stress. The real recovery metric is new growth: expect fresh, flat, vibrant leaves within 3 to 4 weeks of fixing humidity, water, or light. For underwatering, existing leaves may partially uncurl within days. Be patient with calatheas; they’re slow to forgive but generous once happy.
When to give up
Don’t give up on a calathea with curled leaves alone — that’s a complaint, not a death rattle. Only compost if the rhizomes (the thick underground stems) are black and mushy, all roots have rotted, and no firm growth points remain. Even a calathea that loses all its leaves can regrow from a healthy rhizome, so wait a few weeks before making the call.
Frequently asked questions
Will curled calathea leaves uncurl?
Sometimes partially, but badly curled leaves usually keep their shape. Focus on new growth instead — once you fix the humidity, watering, or light issue, fresh leaves will emerge flat and healthy within 3 to 4 weeks. That’s your sign of success.
Should I mist my curling calathea?
Misting helps for about 10 minutes, which isn’t enough to fix chronic low humidity. A humidifier or pebble tray is far more effective. That said, a daily mist won’t hurt as a supplement — just don’t rely on it as the main fix.
Why do calathea leaves curl at night?
That’s normal! Calatheas are prayer plants — they raise and lower their leaves with the light cycle, which can look like curling in the evening. If the leaves flatten out during the day, your plant is just doing its thing, not asking for help.
Can tap water cause calathea leaves to curl?
Yes. Calatheas are sensitive to fluoride and chlorine in tap water, which cause brown edges and curling over time. Switch to filtered, distilled, or rainwater and you may see a real improvement within a few weeks.
How much humidity does a calathea need?
Aim for 60% or higher — calatheas are rainforest plants and struggle below 50%. A small humidifier near the plant is the most reliable fix. Grouping plants together and pebble trays help, but usually can’t reach 60% alone in dry homes.