The most common problem gardeners face when growing tomatoes is leaf curl. This phenomenon can occur on individual plants or on the entire tomato plant and can have several causes. In this article you will learn why tomato plants get leaf curl and how to solve the problem.
Causes of tomato leaf curl
Leaf curling upwards can be caused by lack of moisture and high temperatures. Although it may seem that tomatoes are partially protected from the sun’s rays in the greenhouse, too high temperatures are just as damaging to them as outside. If the temperature in the greenhouse rises above 30 °C, tomato leaves will turn to retain liquid and may suffer burns.
TIP: Shading and ventilating the greenhouse
On hot days, try to shade the greenhouse and be sure to ventilate it. Be sure to water the tomatoes adequately and increase the water rate during hot weather. Recommended watering intervals are:
- Once every 8-9 days at an average temperature of +17-19°C.
- Once every 5 days at +20-24°C
- Once every 2-3 days at +25-30°C
- At temperatures above 30°C, water immediately when the soil is dry
Keep the greenhouse temperature at +19-20°C at night. We also recommend spraying tomato leaves with water early in the morning or late in the evening. You can add various fertilizers to encourage growth.
Excess nitrogen
Another cause of leaf curl may be excess nitrogen. If the stems are very coarse and the upper leaves are curling, stop using nitrogen fertiliser for a few weeks and remove the lower leaves of the plants.
Boron deficiency
If the leaves are curling in different directions, especially at the top of the plant, this may be due to an acute boron deficiency. Compensate for this deficiency by using fertilisers containing boron and magnesium.
Fungal diseases
Leaf curling can also be the result of infection with fungal diseases. Use products to slow the spread of infection or remove infected plants so that others do not become infected.
Mites and root rot
Mites can sit on leaves and cause them to curl. Root rot can be caused by watering too often and too heavily. Analyse your crops well and if it is not a simple reaction to high temperatures or lack of moisture, take the necessary remedial action.
When you see yellowing leaves on cucumbers, tomatoes or peppers, apply this fertilizer
Take good care of your tomatoes and monitor the symptoms to ensure a bountiful and healthy crop. Good luck!
