Tomato Leaf Curl: 3 Main Causes and Ways to Prevent It

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Are you a tomato enthusiast who has encountered the frustrating issue of tomato leaf curl? Picture this: you step into your flourishing vegetable garden, eager to witness the vibrant hues of your tomato plants, only to be greeted by the alarming sight of curled, distorted leaves.

What causes this perplexing phenomenon, and how can you protect your beloved tomato plants from succumbing to it?

In this post, we delve into the three main causes behind tomato leaf curl, unravel the mysteries surrounding this condition, and provide you with invaluable tips to prevent it.

Prepare to embark on a journey of discovery as we unlock the secrets to thriving tomato plants!

What Are The Symptoms of Tomato Leaf Curl:

The leaf curl is more common in indeterminate tomato varieties. A bush variety or the determinate tomato variety is at a lower risk of getting leaf curl.

The curl starts at the leaves that are in the lower position. Then it cups upwards and then starts to roll inwards.

Due to the rolling, the leaves can become thicker or leathery.

Reasons for Tomato Leaf Curl:

A tomato leaf curl can happen due to many reasons. It can be a simple one like fluctuations in weather conditions, or some viral infection that should be taken care of.

Here are some of the main reasons for a tomato leaf curl:

Viral Infection:

A leaf curl in the tomato plant can be due to abnormal growth as an effect of some viral diseases. Some diseases particularly affect the tomato leaves, especially the young leaves and make them curl and twisted.

Initially, the damage might only be limited to the curling of leaves but later it spreads and leaves yellow-green mosaic patterns on leaves.

how to prevent tomato leaf curl

Herbicide Damage:

Leaf curl can also be an effect of herbicide damage. Tomato plants are very sensitive to herbicides. Even herbicides with concentrations as low as 0.1 ppm can harm your tomato plant. It can cause the petioles to bend downwards.

Hostile Weather Conditions:

Most of the time tomato leaf curl happens due to abnormal leaf growth. Abornarl leaf growth happens due to many reasons but the most prominent is environmental stress. It can be due to insufficient moisture, excess nitrogen, high fluctuation in temperature, or excess pruning.

Though leaf curl can happen any time of the year, in most cases when a plant is transferred from a cooler climate to a warmer climate you will see this happening. 

With warm weather, plants need to transpire more which leads to a disbalance of water. So to protect itself from the disturbance the tomato plant curl back some of the leaves and reducing the amount of absorbed heat and reducing transpiration.

A mild leaf curl does not harm your tomato plant in terms of yield. But if the impact is severe the flowers will drop which means lower yield.

How to Prevent Tomato Leaf Curl Problem:

The good news is that it is easy to prevent the tomato leaf curl problem. Once you have identified the source of the problem the solution will be easy.

Some of the causes like heat or wind can be easy to find. You can also do a laboratory analysis of the leaves to find out any viral infection. Herbicide damage though is hard to recognize. Whatever may be the reason you can take some precautionary steps.

Do these simple things to protect your plant against leaf curl:

  • Plant only pest and disease-resistant tomato varieties.
  • Arrange some kind of shade to protect your tomato plant against excessive heat and wind. 
  • Maintain proper moisture levels in the soil. Here is how to efficiently water a tomato plant.
  • Don’t use excessive fertilizer. Especially if your fertilizer has a high dose of nitrogen. 
  • If you are growing indeterminate tomatoes don’t prune them heavily. 
  • Control weeds around the garden. It can reduce virus transmission by insects. 
  • There is no treatment for virus-infected plants. Remove and destroy the infected plants. 


Now that you possess a deeper understanding of the causes and prevention strategies for tomato leaf curl, we encourage you to share this post with fellow gardeners and tomato enthusiasts.

Together, we can create a community of informed growers who support one another in their quest for bountiful tomato harvests. Don’t forget to explore more articles on our site, where you’ll find a treasure trove of knowledge to help you cultivate a thriving garden.

Remember, knowledge is power, but action is the key to success. Implement these preventive measures and watch your tomato plants flourish like never before. Happy gardening!

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prasenjit saha author Gardening ABC

Hi there! My name is Prasenjit and I’m an avid gardener and someone who has grown a passion for growing plants. From my hands-on experience, I have learned what works and what doesn’t. Here I share everything I have learned.