Growing tomatoes is certainly a very fun and rewarding task.
Many people all over the world cultivate tomatoes and there is a lot of info on the internet regarding the successful growing of tomatoes.
However, as with every plant, there are certain problems that may arise, plant pests being one of them.
Another issue that you might face with your tomato plant are white spots on its leaves.
What exactly are the reasons for this and what can you do about it?
Without further ado, let’s just dive right into it!
What’s the Reason for White Spots Tomato Leaves?
One of the main reasons why white spots appear on tomato leaves is powdery mildew. When your Tomato plant is not provided with proper sunlight, air circulation, and humidity, then the leaves start developing white spots on them. These white spots will not kill your plant, but they will reduce its yield and change the taste of the tomatoes. However, if you provide your plant with proper humidity levels, sunlight, fertilization, and air circulation, then you can reverse the effects.
The Main Cause of White Spots on Tomato Leaves
Powdery mildew is the most common cause of white spots on tomato leaves. This is a fungal disease that is caused by the formation of different types of fungi.
These different fungi love to live in dark, moist, and stagnant areas. Thus, when your plant is kept under high humidity levels that are above 70 percent and is not receiving enough sunlight, it starts to suffer.
Powdery mildew is most likely to target younger Tomato plants as compared to older and more well-established ones. This is because Tomato plant owners often over-fertilize their young plants, which causes powdery mildew to form on the leaves.
If you give your plant proper fertilization, it will result in the production of more Tomatoes. If you go overboard, then it can be dangerous for your plant’s health.
Treatment for White Spots on Tomato Leaves
The white spots caused by powdery mildew can have many adverse effects on your plant, but there are several ways to treat them.
Although the effects of powdery mildew can not be completely reversed, if you catch it early, then there is a higher possibility that the treatment will work.
Pruning your Tomato plant encourages growth, but it can also be used as a treatment against powdery mildew. Pruning the infected leaves will prevent the powdery mildew from spreading to other parts of the plant.
It will also improve air circulation and help prevent the growth of powdery mildew in the future. Once you have pruned off the infected leaves, make sure to sanitize your tools to further prevent the spread of powdery mildew.
However, if several of your Tomato leaves have white spots on them, you must only prune off the severely infected leaves. If you prune off too many leaves, then your Tomato plant can die due to the damages.
For the remaining infected plants, simply treat them with fungicide.
Need oil is another treatment for white spots on Tomato leaves since it is an organic fungicide and insecticide.
It will not only keep your plant safe from powdery mildew, but it will also prevent mealybugs, aphids, and whiteflies from attacking it.
Milk spray is a great alternative for neem oil and is also effective in getting rid of powdery mildew. Simply combine three parts water with two parts milk.
Use this mixture to spray infected Tomato leaves. Make sure to apply it on a weekly basis until all symptoms disappear.
How to Prevent Getting White Spots on Tomato Leaves
Keep Distance Between Each Plant
Not providing proper circulation is one of the main culprits behind powdery mildew. Make sure to keep your tomato plants spaced out at least 18-24 inches (46-61 centimeters).
Overcrowding your garden will give the powdery mildew easy access to surrounding plants and damage them as well.
It is also important to provide your Tomato plant with six to eight hours of direct sunlight. But after bathing in the sun for eight hours, you might provide it with shade.
Tomato plants are sun-loving, and thus they should be grown in areas where they can receive full sun.
Planting different varieties of Tomatoes that are naturally resistant to powdery mildew can also help prevent its spread.
Tomato varieties such as Granadero have high resistance against powdery mildew as compared to other varieties.
Thus, if one of your tomato leaves develops white spots due to powdery mildew, it won’t be able to travel to the next plant. This is because the higher resistant plant will be a barrier between the two low resistant Tomato plants.
Other Reasons for White Spots on Tomato Leaves
Although powdery mildew is the number one reason for white spots on Tomato plants, there are still other reasons behind it.
If you have treated your plant with neem oil and even milk spray, but the white spots won’t disappear, then the cause behind them may be different.
Another reason why your Tomato plant may have white spots can be caused by late blight. Late blight is a severe disease that can cause a lot of damage to your Tomato plant.
This disease is most common in areas where the weather is cool and damp. Late blight will cause your Tomato plant’s leaves to die, but before that happens, signs such as white spots or brown spots appear.
These white and brown spots are fungal spots on infected leaves. If you see such symptoms appearing on your Tomato plant, then you need to prune off the infected areas.
Do not use the pruned leaves as compost as the blight can spread to other plants once the compost is added to the soil.
Along with pruning, apply copper fungicide once a week to the infected Tomato plant.
Sometimes Tomato leaves develop white spots because of sun scalding. This is when your plant is exposed to a high amount of sunlight.
This usually occurs when Tomato plants are first kept outdoors after they were grown in an indoor environment. Suddenly giving it bright direct sunlight causes the plant heat damage.
Once your Tomato leaves start to turn white, they will wither and fall off the plant. This will reduce your Tomato plants growth as well as its yield. If Tomatoes were already present on your white-spotted plant, then they might develop some blistery areas.
The best solution to prevent sun scalding is to reduce excess sunlight and provide them with shade. When you first move your plant from indoors to outdoors, you need to provide it with shade.
This will allow your plant to slowly become accustomed to the bright outdoor sunlight. After a week, remove the shade covering and allow your plant to remain under full sun.
Frequently Asked Questions with Regards to White Spots on Tomato Leaves
Do white spots on Tomato leaves mean the plant will die?
White spots on Tomato leaves can be caused due to several issues such as powdering mildew or late blight. It is curable, and if you give your plant the proper attention that it needs, then the plant will not die.
Are white-spotted tomato leaves safe to consume?
While white-spotted tomatoes are safe to eat, the same can not be said for white-spotted tomato leaves. This is because those white spots can be a result of bacterial growth, which is why it is unsafe to consume.
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Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.