Why are the leaves of tomato plants turning white, and what can you do about it?
One of the most common and everyday fruits that are grown all around the world is tomatoes. You can grow tomatoes in pots, containers, in your garden, et cetera, as long as you fulfill their basic needs so they can flourish. If the leaves of your tomato plants are turning white or there are tiny white spots on the tomato plants, then you might have a problem with your tomato plant that needs your uttermost attention.
Tomato leaves turning white and white patches on the leaves of tomato plants are very common issues that can be caused for various reasons. But these issues can be prevented if you have proper knowledge about them.
Because tomatoes have such a long growing season, most people start their tomato plants indoors and then transplant them outdoors once the soil has warmed up consistently. Transplanting tomatoes is tricky, and problems can occur while transplanting seedlings of tomato plants. Tomato plants are vulnerable to too much sun and cold temperatures, which may cause the leaves of tomato plants to turn white (sunscald).
why tomato leaves turn white and why there are white spots and patches on tomato plants.
SUNSCALD (TOO MUCH SUNLIGHT)
Sunscald is a common reason why the leaves of tomato plants turn white. If the tomato plant is exposed to direct sunlight more often than needed, its delicate leaves get burned. Tomato plants planted in a spot where they receive full sun during the day may experience sunscald.
Sunscald tomatoes will begin to develop white or yellow patches on their leaves, which is not something you want to happen to the leaves of your beautiful tomato plants.
Sunscald can affect plants other than tomatoes. Additionally, it may impact strawberries, eggplants, pumpkins, cucumbers, corn, tree leaves, and more.
Sunscald is more sunburn that affects the tomato plants than plant disease. There is no cure for sunscald because it’s not a disease. In actuality, prevention is the most effective treatment for sunscalds.
If your tomato plants are badly affected, you won’t be able to do much to save them.
However, the tomato plant has a good chance of recovering if the stem and growing tips are still green. Eventually, the leaves of the tomato plant, which have turned white, will die and fall.
You can remove white leaves from tomato plants by yourself if the plants are large enough to speed up the recovery process from sunscald because these white leaves will not regenerate, but new leaves may grow in their place.
Sunscald appears to be able to affect big mature plants as well, despite seedlings having a higher risk of suffering from it. A ripe tomato plant will typically experience sunscald on its fruits. Tomato seedlings are easily susceptible to sunscald when grown in lower light levels (indoors) and then suddenly exposed to more intense light levels (outdoors).
How do you protect tomatoes from sunscalds?
Here are some tips for protecting tomato plants from sunscald:
- Grow your tomato plants in proper sunlight conditions to avoid sunscalding.
Harden your tomato seedlings before planting them outdoors.
- More specifically, you must gradually expose your seedlings to direct sunlight if you keep them in an environment where they don’t receive sunlight directly.
- Consider taking your tomato plants outdoors for a few hours each day to harden them off before transferring them to a greenhouse or your outdoor garden.
- Before transplanting the plants, let them spend the first day in the sunlight for about 1-2 hours, then slowly increase the amount of time they spend in the sun for at least seven days.
Other than sunscald, the reason why your tomato plants are turning white or why the leaves of tomato plants have white spots on them can be a fungal disease.
Fungal reasons (disease responsible for white patches on tomato leaves)
Other than sunscald, the fungal disease can be another reason your tomato plants turn white. The fungal infection is primarily caused by overwatering. After transplanting tomato seedlings, water them deeply for two or three days, then once a week or once every other week, depending on the environment.
This encourages the growth of deep roots and prevents the germination of fungus spores. Late blight and powdery mildew are fungal diseases that cause white spots on tomato plants.
Powdery mildew, which several funguses can bring, is a common illness in tomato plants. As airflow and insects like aphids frequently transmit it, it is also difficult to avoid. When the weather is hot, dry, or hot and humid for a prolonged time, powdery mildew is more prevalent. The fungus can also hibernate in compost and plant waste, emerging when the conditions are right.
Because of powdery mildew, delicate white or greyish dust gets collected on the surface of the stems and leaves of tomato plants. This typically begins on the underside of the leaves and is frequently challenging to detect when it first appears. This powdery dust forms white patches on the leaves of tomato plants, making them appear white.
In particular, when the plants are recently fertilized and new, the rapid development of leaves occurs, and the more unique leaves of the tomato plants are more prone to developing the fungus. It can even expand to fruit and flower buds.
Although it’s doubtful that this fungus will kill tomato plants, it can cause lower crop yields and perhaps change the flavour of the tomatoes.
Powdery mildew consumes the plant’s cells, turning the leaves and stems of tomatoes yellow but leaving the plant covered by white mould.
As soon as you notice powdery mildew, it would be best if you act quickly to control it. Your chances of eliminating it increase with how quickly you treat it.
Consider using neem oil or a commercial fungicide safe for tomato plants as a treatment. Bio-fungicides are also effective for treating powdery mildew. Any infected plant parts should be removed.
Until the issue is resolved, follow up with your treatment every week. The tomatoes will generally grow after the fungus is under control.
Methods to Stop Powdery Mildew on Tomato Plants
If there are white patches on the leaves of tomato plants, then you should check if they are affected by powdery mildew. If so, then there are a few points to help you:
- Make sure your Tomato plants are properly spaced for good airflow. For the best results, space your plants 18 to 24 inches apart.
- Ensure that the plants receive adequate sunlight. They should get at least 6 to 8 hours of direct sunlight a day but not intense direct sunlight for more than 8 hours a day, which can lead to sunscald.
- Avoid wetting the leaves; water the soil. The disease may spread if the leaves are wet. For growing tomatoes, an irrigation system is ideal. Although it may be expensive, investing the time and money will pay off in the long run if you intend to grow juicy red tomatoes.
- Don’t compost any plant materials that have been affected by powdery mildew. Instead, burn them or throw them away somewhere else.
- Given the prevalence of powdery mildew on tomatoes, preventative measures are essential. Use a bio-fungicide or sulfur dust once a week when the weather is hot.
- To keep your tomatoes healthy and disease-free, fertilize them frequently. Refrain from over-fertilizing because this raises the possibility of the fungus infecting the plants.
- Prune the plants to promote better airflow.
- Don’t forget to clean your pruning equipment before and after working on infected plant parts.
A severe fungal disease called late blight might be the reason for the big brown and white patches on the leaves of tomato plants. Phytophthora infestans, a fungus, is the root cause of this disease. The tomato plants are killed in a few days by this fungus, which spreads quickly and is highly contagious.
Removing and destroying plants is the only remedy for this disease. Tomato plants infected by late blight should not be included in your compost, as it will spread the disease throughout your garden.
Late blight typically appears in the summer or the fall and more so in rainy conditions. In humid conditions, you might notice a fuzzy white mould on the underside of the leaves. Pale green spots on the leaves of tomato plants are also visible, which turn brown to black. Green tomatoes develop brown spots, and a white mould might also be visible.
Methods to prevent late blight
Some helping points to avoid late blight are:
- You can avoid late blight by regularly applying a bio-fungicide or copper fungicide designed for fungal diseases after rain.
- Do not plant tomatoes close to potatoes. These two plants share the same nutrients and soil type as they are members of the same nightshade family. Additionally, they are prone to the same diseases.
- If planted close to one another, they will start competing for nutrients, making them unpleasant and more vulnerable to late blight.
- If any plant in the garden has late blight, remove the plant or the affected part to protect other plants.
Commonly asked questions about tomatoes
How much watering do tomatoes require?
Although tomato plants don’t require much water, they need to be watered frequently. Tomato plants require more watering during the summer and less watering during the cooler months. Every week, tomato plants require about one to two inches of water.
Which kind of fertilizer is ideal for tomato plants?
Rich soil is ideal for tomato plants, but for healthy growth, the ground must also be supplemented with fertilizer. Because nitrogen and phosphorus are essential nutrients for tomato plant health, fertilizers should contain both elements. Check out this article to learn more about the best fertilizer for tomatoes.
Should I remove the dead leaves from my tomato plant?
Yes, you should remove any tomato leaves that have died. By doing so, space is made available for new growth to appear, and more of the nutrients your tomato needs can be supplied by plant food.
In conclusion, this article has covered a few of the common reasons why tomato leaves turn white and the reason for white patches on tomato plants. Simply relocating the plant out of direct sunlight, assuring it receives more frequent fertilization, or cutting back on your watering practices may solve these issues. We hope this article has been a valuable resource for understanding why tomato leaves turn white, potential causes, and solutions!