Sunburned Tomato Leaves: Causes, Prevention, and Care For Affected Plants

Sunburned tomato leaves are a common challenge that can affect many tomato gardens. This issue arises when tomato plants receive too much direct sunlight, causing the leaves to discolor, wilt, or even appear scorched. This article will delve into what causes sunburned leaves, how to prevent this from happening, and the steps you can take to protect your tomatoes if they are affected. Knowing how to deal with this issue can make a big difference in keeping your tomato plants healthy and productive through the growing season. Let’s get started!

Understanding Sunburned Tomato Leaves

Sunburned tomato leaves can occur when your plants, particularly the developing ones, receive more direct sunlight than they can handle. This often happens after pruning away too many leaves or when a disease impacts your plants, reducing their natural leafy cover. Without this protection, the leaves are directly exposed to the sun.

The intensity of the weather plays a crucial role in the health of tomato plants, particularly in regions like the Deep South, where the sun blazes with an extra degree of ferocity. In these zones, as temperatures soar, even parts of your tomato plants that were once comfortably shaded can find themselves exposed to the harsh, unrelenting sun. This exposure is not just about the increase in light but also the accompanying heat, which can be especially intense in southern climates.

Under such conditions, it’s not uncommon for tomato plants’ leaves to show signs of distress. They might develop pale, discolored patches, a tell-tale sign of sunburn, where the intense sunlight damages or destroys the chlorophyll. In the deep South, where the sun’s rays can be particularly unforgiving during long summer days, this kind of sun damage is a more frequent challenge.

This is why understanding your local climate and its impact on your garden is so important. For gardeners in the Deep South or other extremely hot climes, strategies like providing additional shade during the hottest parts of the day, using reflective mulches to deflect some of the sun’s energy, or even choosing heat-tolerant varieties of tomatoes can be essential in preventing sunburned tomato leaves from the harmful combination of light and heat.

In these warmer regions, where the sun can be both a friend and a foe, balancing sun exposure and protection becomes a critical part of gardening. By adapting your methods to the unique challenges of your environment, you can help your tomato plants not just survive but thrive, even under the scorching southern sun.

Planting tomatoes early in the season can be a smart strategy in hotter regions. This allows the plants to establish themselves and set fruit before the peak of summer heat, thereby reducing the risk of sunburned tomato leaves during the most intense sun exposure.

Preventing sunburned leaves begins with thoughtful pruning. While it’s necessary to manage growth, leaves are essential for providing shade to your plants. Over-pruning can expose them to too much sun, making them more susceptible to burning. Learn exactly how to prune and stake your tomato plants in our companion article.

Maintaining the health of your garden involves carefully managing sun exposure, providing sensible shading, thoughtful pruning, and wise watering practices. Keeping the soil well-mulched and consistently moist can also help the plants cope better with the heat stress. With these approaches, your tomatoes can thrive in the summer while minimizing the risk of their leaves getting sunburned.

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How to Recognize Sunburned Tomato Leaves

Spotting sunburned tomato leaves is pretty straightforward once you know what to look for. The first clue is usually a change in color. You might see patches that start off white, yellow, or a lighter shade of green. Over time, these patches can turn brown or gray, a sign the leaves are struggling with too much sun. These discolored areas often feel dry and might even crack or crumble a bit when you handle them.

Sunburned tomato leaves can appear in a few ways: they might get thin and feel almost like paper or go the other route and turn thick and leathery. It’s like the leaves can’t decide whether they’re drying out or trying to armor up against the sun. You might also see the leaves reacting by curling in on themselves or drooping down. By keeping an eye out for these changes, you can catch sunburn issues early and take steps to protect your plants, ensuring they continue to thrive in your garden.

Sometimes, what looks like sunburn on tomato leaves might actually be a sign of disease, which can make figuring out what’s going on a bit tricky. Diseases like early blight and septoria leaf spot also cause discoloration and can be mistaken for sunburn. The key difference is in the pattern and progression.

Disease spots are often more circular with defined borders and might have a different colored center. They tend to spread in a distinct pattern, unlike sunburn, which usually appears more as a gradual fading or scorching, mainly on the parts most exposed to sunlight. Checking for these patterns can help you distinguish between sunburn and potential diseases, leading to more accurate care and treatment for your tomato plants.

Preventing Sunburned Tomato Leaves

Selecting the right tomato varieties for your growing zone is crucial for guarding against sunburned tomato leaves. Varieties that are resistant to common diseases often have lush foliage, which naturally shields more of the plant from harsh sunlight. Look for tomato plants labeled with “V” or “F,” indicating their resistance to diseases like verticillium wilt and fusarium wilt, which can otherwise reduce the plant’s natural sun protection.

Heirloom tomatoes, with their unparalleled flavors and diverse varieties, don’t necessarily have the same resistance to verticillium and fusarium wilt as many hybrid tomatoes. Hybrids are often bred specifically for disease resistance. While heirlooms may not have the bred-in disease resistance of hybrid varieties, many heirloom tomatoes have thrived through generations, showing a certain resilience.

The susceptibility of heirloom tomatoes to these diseases can vary by variety, so if you’re concerned about this, look for a variety that’s naturally resistant. Enthusiasts of heirlooms often succeed by implementing gardening practices such as crop rotation, proper plant spacing for air circulation, and deep mulch gardening to help mitigate disease risks.

We only grow heirloom plants in our garden and, with good gardening practices, have not had issues with many diseases. Our companion article explains the difference between the types of garden seeds.

Proper spacing is key in your tomato garden. It’s about ensuring good air circulation and balanced sun exposure. This helps keep your plants healthy and less prone to losing the foliage that protects against sunburned leaves. Follow the spacing instructions on seed packets or plant tags for best results. You can read our companion article, which is a guide to growing tomatoes from seeds or seedlings.

A good layer of organic mulch around your tomato plants serves multiple purposes. It helps prevent soil-borne diseases from affecting the lower leaves and retains soil moisture, ensuring stable watering conditions. Consistent moisture is essential to reducing the stress that can lead to sunburned leaves.

Incorporating organic fungicides like liquid copper solutions into your routine can also help protect your tomato plants from diseases that make them vulnerable to sunburn. Remember to reapply these fungicides after heavy rains, which might wash them away. We use Neem Oil in our garden for disease and pest control. Get our recipe for Neem Oil Garden Spray in this companion article.

Using shade cloth can significantly protect your tomato plants from direct sunlight on scorching days. If you have to water your garden, do so before the sun is up or as it is coming up. This allows water to soak in and evaporate before the hot sun bears down on tender plants. Be careful to water the soil and not the leaves to avoid sunburned leaves. Watering at night increases the risk of disease, so if you have to water at night, be certain to water only the soil and avoid wetting the leaves.

Monitor your plants regularly for signs of distress, including disease, pest damage, or insufficient foliage, which can lead to sunburned tomato leaves. Prompt action against these issues is key to maintaining their health and productivity.

Implementing these strategies will prevent sunburned leaves and promote the overall health of your tomato garden. You can enjoy a bountiful harvest with patience and careful observation, even in the face of nature’s challenges.

Sunburned Tomato Leaves: Care and Recovery

If you already see signs of sunburned tomato leaves, don’t worry; all is not lost. Here’s what to do to save your crop and prevent further damage.

1. Identify affected tomatoes. Look for tomatoes with pale, whitish, or light-gray spots, usually on the side most exposed to the sun. These affected areas may look wrinkly or thin and sometimes darken as they age. The tomatoes themselves are still good to eat; just cut away the sunburned spots.
2. Carefully prune, if necessary. If you must remove any surrounding leaves for other reasons, such as disease prevention, do so sparingly. Keep as much healthy foliage as possible to shade the remaining fruit. Be sure to remove and prune any leaves that come in contact with mulch or soil. This prevents the spread of disease.
3. Harvest early if necessary. For tomatoes and tomato plants already showing signs of sunburn or sunscald, as it’s sometimes called, consider harvesting the fruit early, especially if they are near ripening.
   • You can tell a tomato is beginning to ripen when you see the glistening effect on its skin. This is a lightening up of the green as the tomato prepares to take on its mature color. This change is your cue that the fruit is transitioning from its initial growth stage and getting ready to ripen fully.
   • Let them finish maturing off the plant and away from the harsh sun. Don’t leave them attached; further exposure could worsen the condition or invite other issues like pests. I allow mine to ripen on the counter if I pick them before they are ripe. Even if they have odd spots, once they ripen, just cut around the damaged areas – the rest is fine to eat!
4. Consider temporary shade. Although it might sound counterproductive, tomato plants do not necessarily need direct sunlight to ripen. They need to be warm. A light polyester row cover or some 30% shade cloth stretched to block the sun during peak sunlight hours can reduce the risk of further sunburned tomato leaves and tomatoes.
5. Boost your plant’s resilience. Provide balanced nutrition – not too much nitrogen – but sufficient phosphorus and potassium. A healthy plant can better withstand extremes without every stress resulting in damage to the plant and its fruit.
6. Consistent and deep watering is essential for maintaining the health of tomato plants. Watering deeply encourages roots to grow deeper into the soil, where conditions are cooler, and moisture is more plentiful. A deep root system helps the plant withstand hot, sunny days. Ideally, you should water in the early morning to reduce evaporation and ensure the water reaches the roots effectively, preparing the plants for the heat of the day or aiding their recovery afterward.
7. A thick layer of organic mulch around your tomato plants can significantly benefit their health. Materials like straw, grass clippings, or shredded leaves keep the soil cool and moist, insulating against temperature extremes. Deep mulching helps retain soil moisture, reducing the need for frequent watering and keeping the plant hydrated and less stressed, making it less prone to sunburn.
   • You can learn all about deep mulch gardening in our eBook bundle Green Thumb Guides: The Core Five.
8. Reflective mulches, such as silver polyethylene film, protect tomato plants from intense sunlight. These mulches reflect sunlight away from the plants, reducing the intensity of heat and light reaching them. This not only manages temperature but can also help in pest control, as certain pests are deterred by the bright reflection. Using reflective mulch can provide dual benefits of temperature management and pest deterrence.
9. Companion planting can create a beneficial microclimate for tomatoes. For instance, planting taller crops like corn or sunflowers nearby can provide natural afternoon shade. This approach leverages plants’ varying heights and growth patterns for mutual benefit. It also promotes soil health and biodiversity in your garden, with some companions like basil believed to improve tomato flavor and deter pests, establishing a balanced ecosystem where plants support each other.
   • Read all about companion planting for tomatoes in our sister post.

Adopting these measures won’t instantly heal sunburned tomato leaves, but it will prevent the situation from worsening and safeguard your remaining and future harvest. Gardening involves adapting and caring through challenges as well as enjoying the bounty.

FAQs About Sunburned Tomato Leaves

• Can Tomato Leaves Get Sunburned?
  • Yes, tomato leaves can indeed get sunburned, especially when exposed to excessive sunlight without adequate protection. This can lead to discoloration, wilting, and damage to the leaves, affecting the plant’s overall health.
• Why Do My Tomato Leaves Look Burnt?
  • If your tomato leaves appear burnt, it’s likely due to sunburn or sunscald, as it is often referred to. This occurs when the leaves are exposed to intense sunlight for prolonged periods, causing them to dry out, discolor, and develop burnt-looking patches. Other factors such as nutrient deficiencies, diseases, or environmental stressors can also contribute to leaf damage resembling burning.
• What To Do With Sunburned Tomato Leaves?
  • If you notice sunburned tomato leaves, it’s essential to take action to prevent further damage. Start by providing shade to the affected plants during the hottest parts of the day. Trim off severely damaged leaves to encourage new growth and prevent the spread of the damage. Ensure the plants receive adequate water and nutrients to support recovery.
• Can Tomatoes Get Sunburned?
  • Yes, tomatoes can get sunburned, especially if exposed to direct sunlight without protection. Sunburn on tomatoes typically manifests as white, discolored, or unevenly ripened patches on the fruit, affecting its appearance and quality. Providing shade and proper care can help prevent sunburn on tomatoes.
• Will Sunburned Tomato Plants Recover?
  • While some minor sunburn damage on tomato plants may heal over time, severely affected plants may struggle to recover fully. The focus should be on supporting the remaining healthy foliage, providing proper care, and preventing further damage. With proper attention and care, sunburned tomato plants can often recover and continue to produce fruit.
• Can Sunburned Tomato Leaves Affect Production?
  • Yes, severely sunburned tomato leaves can indeed affect the overall productivity of tomato plants. When leaves are damaged by excessive sun exposure, their ability to photosynthesize efficiently can be compromised. Since photosynthesis is crucial for producing plant energy, reducing this process can impact fruit production and quality.
• Are Some Tomato Varieties More Prone to Sunburn?
  • Absolutely. Certain tomato varieties, particularly those with less dense foliage, are more vulnerable to sunburn. Varieties with sparse leaf cover offer less natural protection against intense sunlight. When selecting tomato varieties for your garden, choosing those that do well in your gardening zone and have nice foliage that can provide adequate shade to the fruit and protect against sunburn is beneficial.
• Can Sunburned Tomato Leaves Recover on Their Own?
  • Unfortunately, once a leaf is significantly sunburned, it’s unlikely to recover fully on its own. While some minor damage might heal over time, severe sunburn permanently damages the affected leaves. As a result, the focus should shift to supporting the overall health of the plant and preventing further damage to remaining foliage.
• Is Sunburn More Common at Certain Times of the Year?
  • Sunburn is indeed more prevalent during the peak of summer, especially in regions with intense sunlight and high temperatures. During the hottest months, tomato plants are more susceptible to sunburn due to prolonged exposure to direct sunlight. If you live in an area like the Deep South with extreme summer sun and heat, take proactive measures to protect plants during these times, such as providing adequate shade and proper hydration.
• Does Soil Type Affect Sunburn Risk?
  • While soil type doesn’t directly cause sunburn, the soil quality can influence a plant’s overall health and resilience. Healthy soil provides essential nutrients and supports strong, healthy root systems, which enhances the plant’s ability to withstand environmental stressors like sunburn. So, while soil type may not directly affect sunburn risk, maintaining healthy soil can indirectly contribute to a plant’s resistance to sunburn and other issues.

Wrap UP

Ensuring our tomato plants are shielded from sunburn is essential for their health and the productivity of our gardens. Staying attentive to the early signs of sunburned tomato leaves and taking proactive measures, like careful pruning and providing shade, reflects our commitment to nurturing our plants.

Opting for resilient tomato varieties with ample foliage coverage further bolsters our defenses against the sun’s harsh rays, ensuring our plants remain healthy and productive. Through regular monitoring and timely interventions, we nurture strong growth and abundant fruit production, eagerly anticipating the moment when our sun-ripened tomatoes grace our tables with their flavorful presence.

Recognizing the early signs of sunburned tomato leaves, implementing protective measures with a practical approach, selecting resilient varieties, and carefully tending to our plants will help create a healthy, productive garden. With these practices integrated into our gardening routines, we embark on a journey filled with the satisfaction of cultivation and the reward of a fruitful harvest—a testament to our dedication to sustainable and productive gardens. Happy, Healthy Gardening!