How To Identify Sunscald On Tomato Plants, Control and Prevent Them

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Quick Answer: How To Identify Sunscald And Control Them On Tomato Plants?

Sunscald is a physiological disorder that causes tomato fruits to turn white or blotchy yellow on exposure to heat for an extended period. Plant resistant varieties, pick the fruits early, encourage foliage growth, avoid excessive pruning, and protect the types using a row cover or shade cloth to control sunscald. Sunscald tomatoes are edible after removing the affected areas.

In this guide, I will discuss the identification, control, and prevention of sunscald in tomato fruits.

Shall we dig into the guide?

What Is Sunscald And How Does It Harms Tomato Plants?

Sunscald is the pale and withered coloring on the side of the tomatoes or leaves exposed to the hot sun. It develops fruits with uneven color and bleached areas.

Both leaves and tomato fruits will develop sunscald.

Check out this video on sunscald damage:

How To Confirm That Sunscald Is Troubling Your Tomato Plants?

Check the tomato fruits. You may observe light yellow/ white patches on green or ripening fruits on the side that faces the sun. There may be sunken areas beneath the sunburnt area. Also, the leaves may have white patches on them.

As the patches grow, they may become grayish-white with blisters. These fruits are more prone to rotting and be potential sites for infection.

In the worst scenarios, it can develop black mold.

Here is a useful video on identifying sunscald in tomatoes:

Natural Ways To Control Sunscald On Tomato Plants

The sunscald damage on tomatoes is irreversible, but you may slow the progression. It is important to maintain a good leaf canopy with pruning, fertilization, watering, and pest control.

You may mulch lightly if your soil is warmed.

Physical Ways To Control Sunscald On Tomato Plants

The different physical ways to control sunscald include covering the exposed fruit with lightweight material, including shade cloth, and harvesting the fruits early.

Method 1- Protect The Plants

Protecting the tomato plants using cages, row covers, or shade cloth may help prevent sunscald from affecting the tomatoes.

  • Cage tomato plants- Cover the tomato plants with a cage to shade tomatoes. It may work for determinate varieties.
  • Cover the plants– You may use a lightweight screen or shade cloth to cover the plants when you expect hot, dry weather.

You may watch this video on protecting plants from sunscalding:

Method 2- Harvest The Fruits Early

Harvest the sunscald-affected fruits from the vine before the condition worsens. You may ripen them indoors and consume them after cutting the infected parts.

  • Harvest the fruits early– Harvest them when it starts showing signs of color at the breaker stage to eliminate the risk of sunscald.  
  • Ripen the fruits indoors– You may ripen the fruits indoors. Cut the discolored areas and consume them at the earliest.

Chemical Ways To Control Sunscald On Tomato Plants

Sunscald is a physiological disorder and can not be controlled using any chemical pesticide.

But, you may apply the suggested fungicide, including mancozeb or copper products at 5-10 day intervals to control defoliating diseases that cause sunscald.

How To Prevent Sunscald In Tomato Plants?

The best strategy to avoid sunscalding is to prevent the condition by growing tomato plant varieties that are heat-resistant with heavy foliage.

Practice crop rotation, less pruning, proper sanitation, regular watering, and the use of fungicides to prevent sunscald tomatoes.

Method 1- Avoid excessive pruning

Reduce excessive pruning on the tomato plants in regions with sunny, hot climates or with a history of experiencing sunscald.

The extra branches may provide extra shade. Use a tomato cage or row cover to avoid the requirement for pruning.

Method 2- Choose Appropriate Varieties

Choose heat-tolerant varieties if you live in regions with hot, long summers. You may also grow plants upside-down to shade the fruits.

Method 3- Prevent Diseases

Keep tomato plants free from diseases, including tomato wilts, blights, and leaf spots that cause foliage to drop. 

You may also grow disease-resistant varieties. Maintain proper airflow between plants and remove infected or diseased parts.

Method 4- Avoid overhead irrigation

Overhead irrigation may lead to diseases that may defoliate the plant and harm the fruit quality. So, avoid overhead irrigation and may use soaker hoses or drip lines along the base of the plants.

Water sufficiently and add mulch to avoid stress.

Check out this video on preventing sunscald in tomatoes:

What Causes Sunscald In Tomato Plants?

Sunscald tomatoes are caused due to exposure to harsh sunlight for an extended period during hot weather. Severely pruned plants or plants that have lost foliage due to disease or pathogens are more susceptible to sunscalding.

Insufficient nutrients may also contribute to inadequate foliage. The highly stressed plants don’t produce lush, healthy leaves to support the fruits.  

Lastly, a lack of nitrogen may contribute to sunscalding.

Frequently Asked Questions

Are sunscald tomatoes safe to eat?

Yes, you can eat sunscald tomatoes after slicing the affected parts. Take care that it does not have black mold. It is not safe to eat fruits with mold as they may harbor pathogens and so, discard them.

Which vegetables are affected by sunscald?

Sunscald primarily affects tomatoes, summer squash, zucchini, pumpkin, and peppers. It can also occur after harvest in eggplant, cucumbers, watermelon, and squash. Also, it can happen in almost any fruit or vegetable that can affect before and after harvests.

What does sunscald look like on tomato leaves?

The sunscald-affected tomato leaves develop gray-white blotches on the upper portions of the leaves in hot and sunny weather. It primarily affects the transplants shortly after planting.


I hope the guide has provided you with many tips and tricks for avoiding sunscalds in the future and protecting your fruits.

We hope that this article was helpful in understanding the causes and remedies for sunscald in tomatoes, and if you have had any of your own experiences with this common tomato problem, please share it with us.

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