9 Reasons Your Tomato Leaves are Turning Purple and Their Fixations?


Tomato plants turning purple due to several factors, including a lack of phosphorus, potassium, magnesium, and nitrogen. Environmental conditions, genetic factors, and diseases or pests

Nutrients are essential for plant growth, and without them, the plant may exhibit purple leaves and stems. Tomatoes can also turn purple because of things in the environment, like sudden changes in temperature or bad weather.

Additionally, certain genetic traits may cause the plant to develop purple pigmentation. Diseases and pests can also contribute to the discoloration of tomato plants.

Tomato plants are heavy feeders; they require a lot of attention to grow healthy. Some varieties are naturally purple, like Indigo Rose, but some are caused by not taking proper care of plants.

If you are worried about tomato leaves turning purple, look no further! In this article, I will tell you the reasons why leaves turn purple and the best solutions to prevent these problems. Let’s start.

Purple tomato leaves

9 Reasons Your Tomato Leaves Turning Purple

Tomato plants with purple leaves are a serious problem. Sometimes it is natural, and you should not be concerned, and other times it is caused by deficiencies, environmental factors, transplant shock, or other diseases.

Identifying the specific cause of purple leaves is essential to taking appropriate measures to maintain the plant’s health.

Here are 9 reasons your tomato plant leaves turning purple and how do you fix purple tomato leaves. These are given below;

1. Nutrient Deficiencies

Tomato leaves turning purple due to a nutrition deficiency, particularly a lack of phosphorus, potassium, and magnesium.

Phosphorus is an important part of many biological processes, such as photosynthesis, the transfer of energy, and cell division. When a tomato plant does not receive enough phosphorus, it may exhibit purple leaves and stems.

When there is a deficiency of magnesium, the plant does not produce chlorophyll, which results in poor and stunted growth. You can also use magnesium sulfate to supplement your magnesium deficiency.

Potassium helps in growth and improves flowers. It is essential for the development of fruit production. It plays an important role in chlorophyll and photosynthesis.


To fix the nutrient deficiency in tomato plants;

  • Apply a phosphorus-rich fertilizer or add organic matter like compost or other mulches to the soil.
  • Adjusting the pH level of the soil can also aid in phosphorus absorption.
  • Do proper watering and avoid the tomato plants to face extreme weather conditions.

This helps a lot with plant health and growth.

2. Transplant Soil

Soil that is used for plants

If you put tomato plants in soil that doesn’t have enough of what they need, like phosphorus and nitrogen, or has the wrong pH level, the leaves will turn purple. A lack of proper nutrients can lead to many problems.

There are two kinds of mulch for tomato plants: organic mulch and inorganic mulch. The best one is organic marrow. You can mix the mulch with soil or sprinkle it around the tomato plant.

To make sure tomato plants grow well, the soil must be properly prepared before they are moved. Soil has a pH of around 6.0 to 6.8. Most soil fertilizer is rich in nutrients, but adding mulch to the soil can improve the growth of plants.


To fix the soil on tomato transplants that causes purple leaves, it’s important to determine the cause of the issue.

  • If the cause is a lack of nitrogen, adding a nitrogen-rich fertilizer to the soil can help.
  • Soil pH is also critical, and maintaining it in the range of 6.0 to 6.8 can help the plant absorb nutrients efficiently.
  • Adding organic mulches to the soil can also improve its quality and prevent nutrient deficiencies that lead to purple leaves.

3. Viral Infections

Viral infections are the major reason for purple tomato plants. Some viral diseases, such as tomato mosaic virus, verticillium wilt, bacterial wilt, and tomato spotted wilt virus, can cause leaf discoloration, including purpleing and yellowing of the leaves.

These viruses can also cause other symptoms, such as stunted growth and reduced fruit production. Most of the time, infected plants or insects carry viruses, so it’s important to take steps to stop these infections.

You can use disease-resistant tomato varieties for this. The viral infection spread due to the use of dirty gardening tools. Using clean gardening tools can help reduce the risk of viral infections in tomato plants.


There is no cure for viral infections in tomato plants. But, as you know, prevention is better than cure. You can protect tomato plants by;

  • using disease-resistant varieties, good garden hygiene, proper plant care, and controlling pest populations.
  • If a viral infection is detected, the infected plant should be removed and destroyed to prevent the spread of the virus.

4. Sunburn

Proper Sunlight for plants

Sunburn is a type of stress that can cause tomato plants to develop purple leaves and sometimes burn the whole plant. Excessive exposure to intense sunlight can cause the leaves to take on a purple or brown appearance.

Daily, plants need six hours of direct sunlight, or you can shade your plants with a net. Giving tomato plants continuous sunlight causes leaf burn and other issues. Sunburn can be prevented in tomato plants by giving them time to get used to direct sunlight, giving them enough shade, and exposing them to sunlight gradually.


To fix sunburn in tomato plants;

  • It is essential to provide shade and gradually increase sunlight exposure.
  • Adequate soil moisture and fertilization can help promote plant health, reducing the risk of stress-related issues.
  • Removing damaged leaves can also help the plant recover and produce new, healthy growth.

5. Stress On Plant

Stress can cause tomato plants to turn purple. This stress can be caused by changes in temperature or humidity, extreme weather, or a lack of water. Tomato plants are heavy feeders; they need everything in their required amount for growth.

When a plant is stressed, it may move resources to other parts of the plant to protect itself. This can cause anthocyanin to build up, which makes the plant look purple. This stress can manifest itself in the leaves and stems of the tomato plant.

Do proper watering; give your plants water daily early in the morning, and in summer, water your plants twice a day. If your plant is facing extreme weather, protect it. Provide your plants with high-nutrient soil and organic matter.


The main reason for stress is caused by;

  • Environmental factors, such as changes in temperature, humidity, or exposure to extreme weather conditions.
  • The plant responds to this stress by redirecting its resources, which can result in the buildup of anthocyanin, leading to purple pigmentation in the leaves and stems.

That’s how you can take proper steps to protect against purple tomato leaves and improve the growth of tomato plants.

6. Pests and Diseases

Pests and diseases can cause tomato plants to change color, such as by making the leaves turn purple.

For example, spider mites, aphids, hornworms, whiteflies, and thrips are common pests that can infest tomato plants and cause damage, leading to purple or brown spots on the leaves.

Similarly, certain diseases such as the tobacco mosaic virus, verticillium wilt, and bacterial wilt spots can also cause purple spots on the leaves.


To fix the issue of pests and diseases;

  • It’s essential to identify the specific pest or disease then take appropriate control measures.
  • This can include using insecticides, natural predators, using disease-resistant tomato varieties, practicing good sanitation, and monitoring the plants for signs of infestation or disease.

7. Intense Light

When tomato plants are exposed to intense light, it can cause the leaves to turn purple. This is a natural response to stress and does not cause any harm to the plant. It’s good to give light to the plants because it helps with growth.

If you are growing tomatoes in a container, you can put the container close to the window. That’s how plants receive light, and air circulates around the plants. Plants, on the other hand, require shade; providing light to plants 24 hours a day results in leaf curling and other plant damage.

For this, growers can provide shade or move the plants to an area with less intense light. It can help maintain the plant’s healthy growth and prevent discoloration of the leaves.


To fix purple leaves from intense light;

  • Provide partial shade, adjust watering, and ensure enough phosphorus.
  • Use shade cloth, avoid over-watering, and apply a phosphorus-rich fertilizer.

8. Environmental Factors

Environmental factors can play a significant role in causing tomato plants to turn purple. When you transplant tomatoes, all you can do is hope for good weather conditions because it plays an important role in plant growth. The plant’s purple color can be caused by changes in temperature and water stress, such as too much water.

Extreme weather conditions, such as high winds and heavy rains, can also cause tomato plants to change color. A lack of nutrients, like phosphorus, can cause purple leaves and stems if the soil isn’t good and it isn’t fertilized right.


To fix environmental factors, all you can do is;

  • You can use a shade cloth or change the location of the plant to a more stable location.
  • Providing adequate water and preventing overwatering can help to reduce water stress.
  • Providing windbreaks or using row covers can help in extreme weather conditions.
  • Monitoring and adjusting soil pH levels can also help optimize the growing environment.

9. Tomato Purple Leaf Disorder

Purple leaf disorder

Tomato purple leaf disorder is caused by a virus and is due to phosphorus deficiencies.

The disease appears in the form of purple spots on tomato leaves after transplanting the tomato seedlings. In some cases, tomato seedlings turn purple and the growth stops.


As you know, there is no cure for the viral infections but all you can do is;

  • Protect purple leaves on tomato seedlings by pulling out that part of the plant which is affected by the virus to not spread the disease all over the plant.
  • Avoid transplanting tomatoes too early because young plants do not have much power to fight against weather conditions. This is the other reason for tomato plant purple leaves.


In conclusion, purple leaves on tomato plants can be caused by a lack of phosphorus, environmental factors, genetic traits, pests and diseases, or a lack of phosphorus.

To fix the problem, you need to figure out what’s causing it and take the right steps, like giving them enough food, water, and protection from pests and diseases. Proper care can help maintain the plant’s health and productivity.

You can easily learn how to prevent your tomato leaves from turning purple by reading this article.

Thanks for reading!

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