A plant curls its leaves to cut down on water loss or to cope with stress. Which way the leaf curls, and what else you see, points to the cause.
What the curl tells you
- Leaves curl inward or fold, soil is dry. Thirst or heat. The plant is reducing its surface to hold water.
- Leaves curl downward and look yellow or soft, soil is wet. Too much water.
- Leaves curl and look scorched at the edges. Too much direct sun or hot, dry air.
- New leaves are curled, twisted or distorted, often with sticky residue. Sap-sucking pests such as aphids or thrips.
- Leaves curl after a cold night or a draught. Cold stress.
What to do
- Check the soil by hand before doing anything. Dry means water thoroughly. Wet means wait.
- Move the plant out of harsh midday sun, heaters and cold draughts.
- Look under the leaves and along new growth for insects, and wipe them away with a damp cloth.
- Keep watering steady. Avoid long dry spells followed by soaking.
When to scan
If new leaves keep coming out curled or twisted, take a close-up of a new leaf and a photo of the whole plant in daylight and scan it.