Common Tomato Problems and What Causes Them
Owen Petrakis · Oct 22, 2026 · 7 min read
Quick answer
Blossom end rot, split fruit, curled leaves, and blight — what each looks like and how to prevent it.
Tomatoes are one of the most popular crops for home gardeners, and one of the most likely to develop problems.
Most issues come down to watering, weather, or a handful of common diseases.
1 Blossom end rot
A dark, sunken patch on the bottom of the fruit is caused by calcium not reaching developing fruit, usually because of irregular watering. The fix is consistent watering, especially in pots and grow bags. Affected fruit will not recover, but new fruit should be fine once watering evens out.
2 Split fruit
Fruit splits when a dry spell is followed by heavy watering or rain, and the skin cannot keep up with sudden growth. Again, steady watering is the solution.
3 Leaf curl
Leaves rolling upward are often a response to heat, wind, or heavy pruning and are usually harmless. Twisted, distorted new growth can point to herbicide drift or aphids.
4 Blight
Late blight causes brown patches on leaves and stems that spread rapidly in warm, wet weather, followed by rotting fruit. Remove and dispose of affected plants (not on the compost heap). Growing under cover, spacing plants for airflow, and choosing blight-resistant varieties all help.
5 General prevention
- ✓Water at the base, not over the leaves
- ✓Feed weekly with tomato fertiliser once flowering starts
- ✓Remove lower leaves touching the soil
- ✓Rotate where you grow tomatoes each year
This is general gardening information. Results depend on your climate, soil, and conditions. Follow label directions for any fertiliser or treatment, and check whether plants are toxic to pets or children before bringing them home.