When tomato leaves curl in summer, heat stress is often the first thing to check. Hot temperatures, dry soil, irregular watering, pests, and excessive pruning can all make tomato leaves curl.
If the plant is still green, growing, and producing fruit, the problem may only be temporary. Start with the simplest checks before making major changes.
Tomato plants enjoy warm weather, but extreme heat can cause stress. During very hot afternoons, leaves may curl upward as the plant tries to reduce moisture loss.
If the leaves remain mostly green and the plant still looks healthy, heat is often the main cause. During unusually hot weather, light afternoon shade can help.
Uneven watering can make tomato leaf curl worse. Avoid frequent shallow sprinkling. Instead, water deeply enough to moisten the root zone and check the soil before watering again.
The goal is consistent moisture, not constantly wet soil. Tomatoes growing in containers may need more frequent checks because pots dry out quickly in summer.
Check the undersides of curled leaves for tiny insects, sticky residue, discoloration, or damaged new growth. Aphids and whiteflies can cause curling and distortion.
If pests are present, identify them before choosing a treatment.
Tomato leaves help shade developing fruit and stems. Removing too much foliage during hot weather can expose the plant to stronger sunlight and additional stress.
Prune only when necessary for airflow or to remove damaged growth.
Curled leaves are more concerning when they appear with severe yellowing, unusual spots, badly distorted new growth, stunted plants, or heavy pest activity.
If only a few leaves curl during hot weather and the plant remains productive, monitor it and focus on reducing stress.
Summer tomato leaf curl is often a response to heat or watering stress. Check soil moisture, inspect for pests, and avoid excessive pruning before making major changes.
Save the infographic above so you can quickly check these causes whenever curled tomato leaves appear.