Tomato is one of the plants that many people love to grow in every home garden. This plant can both be grown for decoration and harvested fruit to serve each nutritious meal. Tomatoes are used to prepare many attractive dishes, especially salads with vegetables and different fruits.
Tomato plants have many different varieties, and fruit sizes and colors are also different. You can find small red, yellow, green, purple, etc. Tomato plants are relatively easy to grow, easy to care for, and don’t take much effort to fertilize. However, one of the most common phenomena that you may encounter when caring for this plant is a condition where the leaves turn white. Why are my tomato leaves turning white? What is the cause of this condition? How to prevent and fix it? Let’s find out the detailed causes and solutions to revive your tomato plants.
Why Are My Tomato Leaves Turning White?
The fact that the leaves of tomato plants turn white is associated with a variety of causes. Some of the most common causes are overexposure to the sun, cold temperatures, too much or lack of nutrients, or fungal diseases.
Too Much Sun (Sunscald)
Sunlight is an extremely important factor for the growth of any plant. Plants will carry out photosynthesis and metabolism when there is sunlight. From there, they will regenerate and grow new cells continuously.
However, each plant species has different needs for sunlight. Tomato plants need sunlight every day to photosynthesize, metabolize and stimulate the growth of new cells. However, the leaves of tomato plants are very sensitive to excessive sun. They will show signs of white spots, brown spots, yellow spots appearing, or leaf edges drying and turning brown.
If tomato plants are exposed to intense sunlight all day, they will get sunburned. From there, pale yellow or white patches will appear on the leaves. Depending on the intensity of the direct sun, dark spots may also appear or the edges of the tomato leaves will dry, curl and turn black.
Solution for sunscald
If the entire leaves of tomato plants have turned white and curled up, recovery is difficult. The reason is that sunscald is not a disease, so you cannot use a specific medicine. However, if the number of leaves turning white is only a small part of the tomato plants, you still have a chance to revive them.
If you are growing tomato plants in pots, you should move to a cool location, out of direct sunlight, and well ventilated to reduce light pressure for tomato plants. If the tomato plants are planted in the ground, you can cover them with straw or a canopy to keep the sun out of the tomato plants for many hours. In addition, you can also apply an all-purpose fertilizer to the surface of the soil around tomato plants to improve resilience and promote overall plant health.
Tomato plants will often experience sunscald if you grow them in gardens or areas without a canopy. The time when tomato plants are most susceptible to sunscald is when transplanting. Usually, when you grow young tomato plants outdoors, they are very susceptible to damage from direct sunlight. When young tomato plants have been affected, they will not have enough energy to grow normally.
Therefore, you need to grow tomato plants in nurseries or indoor environments until they are established. You can get them used to the sun every day and increase the time before planting them completely in the ground. Should plant them in the cool afternoon to limit the sun to wilt the young tomato plants.
You can move pots with young tomato plants outside in a shaded and sunny area for a short amount of time each day. This period lasts up to 2 weeks so that the young tomato plants have enough time to get used to and harden before starting a new environment.
The Temperature Is Too Cold
Tomato plants are plants that are not resistant to low temperatures. If the weather is too cold, tomato plants will become sensitive to temperature and seriously affect health. The response of tomato plants is to close the cells to trap heat and protect them from deformation. If tomato plants are subjected to extremely cold temperatures for a long time, their leaves will appear white patches.
Solution for temperature
If you grow tomato plants in pots, you can move them indoors or in warm areas when temperatures get too cold. Because tomato plants can’t tolerate low temperatures, they will suffer from heat shock, stunt, or die.
Use pergolas, plastic bags, or straws to cover the tomato plants when the temperature is low to keep them warm. During this time, you also need to avoid cold winds because they will cause serious damage to tomato plants such as damaged leaves, broken branches, or broken stems.
Prevent cold temperatures
To avoid damage to tomato plants from low temperatures, you should research and choose the best tomato varieties for the climate where you live. Currently, many different varieties of tomatoes can be transplanted to suit each climate zone.
However, you should still only plant young tomato plants in the ground when the soil temperature is above 60 degrees and the weather is no longer frost. Tomato plants will face many health problems if they are exposed to temperatures below 50 degrees for several hours a day.
You should also monitor the weather forecast for frosts or extreme weather to take precautions to protect tomato plants. Grow them in a nursery or use a covered trellis to keep out snow and frost. You must take measures to keep plants warm and avoid the negative effects of extreme weather for many days.
Lack Or Excess Of Nutrients
The leaves of tomato plants turning white can also be related to a lack or excess of nutrients. Plants lacking nitrogen or phosphorus will cause the leaves to turn white or yellow. Tomato plants can be deficient in some common nutrients such as calcium, magnesium, nitrogen, or phosphorus. In addition, a deficiency of calcium or magnesium will also cause the leaves to turn white, but the veins will remain green.
In addition, excessive fertilization also causes stress for plants. From there, the leaves of tomato plants will have white, yellow, or brown spots appear. If the amount of fertilizer is too large, it will also burn the leaves of the plants. They will turn brown mass and roll up because the cells have been completely deformed.
The nutrients and minerals needed for tomato plants are found in specialized fertilizers. Fertilizers for tomato plants will help them always have enough nutrients and maintain the green color of their leaves.
Once you have determined that the cause of the leaves of tomato plants turning white is a lack of nutrients, you should add fertilizer to the plants. The ideal fertilizer would include substances such as nitrogen, phosphorus, and potassium. In addition, calcium and magnesium are also necessary for the healthy growth of tomato plants. In addition, you can use organic fertilizers from cow manure and straw soaked in water. This organic fertilizer contains nitrogen and phosphorus, two of the most essential nutrients for tomato plants.
However, you should also not overuse fertilizers to stimulate the growth of tomato plants because over-fertilizing will cause leaf burn and excessive stress on the plants. To deal with excess fertilizer, you need to drain the soil, soak it in water, or replace it with new soil to avoid overstressing the plants.
Preventing undernutrition and excess
To prevent nutrient deficiencies or over-fertilization, you need to follow the manufacturer’s instructions for each fertilizer. Each fertilizer has detailed instructions on when and how much to use each time for each growth stage of tomato plants.
Therefore, you need to follow the golden times to supplement nutrients for plants. You may prefer to use organic or slow-release fertilizers to ensure that the plants can absorb nutrients slowly.
Fungal diseases are also a common cause of white spots on the leaves of tomato plants. The appearance of fungi and pests is associated with a humid environment. In particular, improper watering, excessive watering, and poor drainage are the causes of waterlogging and root rot.
A humid environment will create favorable conditions for fungi to grow. From there, they release spores from the fungus into the air, and they attack the leaves of plants whenever they attach. Alternaria, or Septoria leaf spot are common fungal diseases of tomato plants.
Solution for fungal diseases
Depending on the extent to which the fungus attacks tomato plants, you need an appropriate solution. If the number of leaves turning white is not much, you only need to remove the diseased leaves to avoid spreading to other healthy leaves. Then you use specialized fungicides to spray directly on the entire plant.
During this time, you need to limit watering and avoid making the environment too wet. Because a humid environment is an ideal environment for fungi to multiply and thrive. In addition, you should also regularly clean the soil after each new plant planting because harmful fungi and bacteria will hide in the soil and attack the plants when the environment is favorable.
Prevent fungal diseases
The main reason that fungi thrive is due to a humid environment. Objective factors such as high humidity, and rain for many days make the soil wet and waterlogged. In addition, subjective factors such as improper watering, over-watering, and poor drainage will cause root rot and create favorable conditions for fungal growth.
You should only water when the ground is 1-2 inches dry. The soil needs to be well drained to avoid accumulating excess water and causing waterlogging. You should also not water according to the available schedule. Instead, water according to actual water needs from the tomato plants and climate from time to time. You should avoid watering at night or on the leaves of tomato plants because fungal spores will grow quickly when the environment is humid at night.
The leaves of tomato plants turning white have various causes such as too much sun exposure, too cold temperatures, and lack or excess of nutrients. Finally, fungal diseases also cause white spots to appear on the leaves of tomato plants.
To prevent these conditions, you need to create an ideal environment for tomato plants. Use awnings to keep out intense sunlight, cold winds from extreme heat, or snow days. In addition, you also need to fertilize to provide adequate nutrients for tomato plants. From there, plants will have enough energy and stamina to withstand the negative effects of the weather.