Most likely cause
Underwatering is the leading cause of curling on a Snake Plant. Although these plants are famously drought tolerant, they are not drought proof, and when the soil stays dry for too long the leaves give up their stored water and curl inward to reduce the surface losing moisture. The leaves often wrinkle lengthwise and feel slightly soft rather than firm.
Confirm it by checking the soil and the leaves. If the soil is dry all the way down, the pot feels light, and the leaves are wrinkled and bendy rather than mushy, thirst is the cause. Water the plant thoroughly until it drains from the bottom, and within a day or two the leaves should plump and straighten. If they stay soft and the soil is wet, suspect root rot instead and inspect the roots.
Other causes
These rank below underwatering but each produces telltale curling.
- Root rot. Overwatering rots the roots so they cannot take up water; leaves curl despite wet soil, the base feels soft, and roots are brown and mushy.
- Pests. Thrips or spider mites drain sap and distort growth; look for curling with silvery stippling, tiny insects, or fine webbing in the crevices.
- Cold damage. Temperatures below about 50 degrees Fahrenheit stress the leaves; curling follows a cold snap or a spot near a chilly window or door.
- Too little light. In deep shade new growth is weak and may curl or grow distorted as it reaches for light.
- Crowded roots. A pot packed tight with rhizomes dries out fast and struggles to hold water, leaving leaves prone to curling.
How to fix it
- Check the soil and pot. Feel deep into the soil and lift the pot. Bone-dry, light, and wrinkled leaves point to thirst.
- Water thoroughly. Soak the soil until water drains from the bottom, then let it dry out completely before watering again.
- Inspect the roots if soil is wet. If leaves curl with wet soil, unpot and check; trim any soft brown roots and repot in fast-draining mix.
- Check for pests. Look over both leaf surfaces and the crevices, and treat any thrips or mites with insecticidal soap or neem oil.
- Warm it up. Move the plant away from cold drafts and windows, keeping it above about 55 degrees Fahrenheit.
- Brighten the spot. Give it bright indirect light so new growth comes in firm and upright.
- Repot if root-bound. If the pot is packed with rhizomes, move up one size into gritty, fast-draining mix.
| Cause | Tell-tale sign | Fix |
|---|---|---|
| Underwatering | Dry soil, wrinkled bendy leaves | Water thoroughly, then let it dry fully |
| Root rot | Wet soil, soft base, mushy roots | Trim rotten roots, repot in fast-draining mix |
| Pests | Stippling, webbing, tiny insects | Treat with insecticidal soap or neem oil |
| Cold damage | Curling after a cold snap | Move to a warmer, draft-free spot |
| Too little light | Weak, distorted new growth | Move to bright indirect light |