One of the most common issues you can face when growing tomatoes is when their leaves curl. This can be alarming for those who are new to growing tomatoes, but the good news is that there are several reasons why this happens and ways to fix it.
Essentially, tomato leaves curl as a sign of stress. The plant is unhappy for some reason and is curling its leaves to protect itself.

There are several reasons why tomato leaves may curl including:
Incorrect Watering
Overwatering or underwatering can both cause tomato leaves to curl. The plants need consistent moisture, so watering them deeply and regularly is important. Avoid watering the leaves themselves, as this can lead to fungal infections.
High Temperatures
Tomato plants are sensitive to temperature changes, and high temperatures can cause the leaves to curl as a defense mechanism. If you're experiencing a heatwave, make sure to provide shade for your tomato plants.
Low Temperatures
Conversely, tomato leaves can also curl when the conditions are too cold.
Tough Growing Conditions
Tomato plants can be affected by a variety of environmental factors, including poor soil quality, pests, and diseases. Make sure to provide your plants with the right growing conditions, including fertile soil, proper drainage, and protection from pests.
Nutrient Deficiencies
Tomato plants need a variety of nutrients to grow properly, including nitrogen, phosphorus, and potassium. If your plants aren't getting enough of these nutrients, the leaves may curl or turn yellow.
Over Fertilisation
Excessive nitrogen fertilisation can cause tomato plants to grow too quickly and become more susceptible to stress and disease.
Insect Infestations
Certain insects, such as aphids and whiteflies, can cause tomato leaves to curl. Make sure to monitor your plants for signs of insect infestations and take action if necessary.
Fungal Infections
Fungal infections can also cause tomato leaves to curl. Make sure to keep the leaves as dry as possible and avoid overcrowding your plants.
Genetic Factors
Some tomato varieties are more prone to leaf curl than others due to genetic factors. If you're experiencing leaf curl with a particular variety, try switching to a different variety that is better suited to your growing conditions.
What To Do About Leaf Curl
The key thing to do is identify why your tomato plant is stressed. Is it too hot? Has your watering been erratic? Does it have pest issues?
Check plants daily for any signs of curling leaves, yellowing, or wilting. Early detection can help prevent the spread of disease and reduce the risk of plant damage.
Once you have worked out what is causing the leaf curl and corrected it the problem should resolve itself when given a little time.
Conclusion
The causes of this issue can range from environmental stress to disease and pests. However, with the right care, it is possible to fix the problem and ensure a healthy tomato crop.
One of the first steps to take when dealing with tomato leaf curling is to identify the cause of the problem. This can be done by examining the leaves for signs of damage or disease and checking the soil moisture levels. Once the cause has been identified, steps can be taken to address the issue.
Some common causes of tomato leaf curling include over or under watering, excessive pruning, transplant shock, excessive nitrogen, disease, pests, and herbicide damage.
Frequently Asked Questions
What are the symptoms of tomato leaf curl disease?
Tomato leaf curl disease is characterized by the upward curling of tomato leaves. The leaves may also become thick and leathery and may exhibit yellowing or discolouration. In severe cases, the plant may exhibit stunted growth or die.
What causes tomato leaves to become thick and leathery?
Tomato leaves may become thick and leathery due to a variety of factors, including overwatering, nutrient deficiencies, and disease. Providing proper watering and fertilization, as well as monitoring for disease, can help to prevent thick and leathery leaves in tomato plants.
Can overwatering lead to tomato leaf curl?
Yes, overwatering can lead to tomato leaf curl, as it can cause the roots to become waterlogged and reduce the plant's ability to absorb nutrients. Proper watering techniques, such as allowing the soil to dry out between waterings, can help to prevent leaf curling due to overwatering.
Is it possible for plants to recover from leaf curl?
Yes, plants may be able to recover from leaf curling if the underlying cause is addressed. However, if the leaf curling is due to a viral infection or other serious condition, the plant may not be able to recover. Regular monitoring and proper care can help to prevent leaf curling and promote plant health.





Colin M says
Looks like you covered every scenario, In Tenerife the problem was the very hot wind and breeze, we had a yellow colured power we used to dust the leaves with a least once a week not been able to find it in the Uk yet