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Why are My Tomato Plant Leaves Turning Yellow? Damage Sign!

Why are my tomato plant leaves turning yellow or brown? Should I be worried? Most importantly, what should I do to save my tomatoes?

These are the questions that some gardeners encounter when growing tomatoes for the first time. If you have recently experienced this and not sure of what to make up of it, this article provides you answers along with some related inquiries, most importantly the solutions.

There’s nothing to worry about if you see the leaves of your tomato plants turning yellow. That’s because the solutions are easy and manageable. These are often due to nutritional deficiencies, watering problem, insufficient sunlight, pests or diseases.

Why Are My Tomato Plant Leaves Turning Yellow?

1. Less Or Too Much Watering

Why are My Tomato Plant Leaves Turning Yellow

Tomato leaves turn yellow because of inadequate water. It is not a new problem as this is one of the essential requirements for every plant to grow. Make sure that you water them regularly, and more often during hot temperatures.

Lack of enough water is also a cause of the yellow leaves. You need to water once after 5 to 7 days only. But if it’s summer and dry, water every 2 to 3 days. Do not allow the soil to become dry and soggy.

Why are My Tomato Plant Leaves Turning Yellow

In addition, it’s best to water very early in the morning. You also have to be careful when pouring water at the base as you don’t need to shower above the leaves or upper stems.

2. Deficiency Of Nitrogen

When’s the last time you checked the soil regarding nitrogen levels? It has probably decreased and need fixing immediately. Once you have the soil result and it’s a low level, you need to supplement it with manure, compost or fertilizer that is rich in nitrogen.

Why are My Tomato Plant Leaves Turning Yellow

The lack of nutrition, particularly this compound, can indicate why the leaves are yellow or brown. If only the bottom leaves are yellow, it’s probably a soil problem. Just remember that you do not add a lot of nitrogen as this can burn the plant.

3. A Pest Or Disease

Another reason why tomato plant leaves are yellow is because of the presence of a disease or a pest. It can be fungal or viral disease when the yellow leaves at the bottom are spread upward.

Why are My Tomato Plant Leaves Turning Yellow

The common signs of an early fungal disease in tomatoes are yellow leaves with small spots or bulls-eye like lesions. This doesn’t necessarily infect the fruits but eventually if the disease is already severe.

If it does, it’s considered a late blight that is indicated by the upper leaves and stems having oily lesions. It can be a curly top virus or fusarium wilt. Regardless, you can treat with chlorothalonil, which is a fungicide for plants, including tomatoes.

The other disease can be from a virus. When it comes to viral diseases, there are potential threats to name. These include cucumber mosaic virus, tomato mosaic virus, single streak virus, tomato yellow leaf curl or tobacco mosaic virus.

You can easily identify that this is the cause if there are mosaic patterns on the leaves.

Why are My Tomato Plant Leaves Turning Yellow

Most often, the development of viral diseases in tomatoes are initiated by pests, such as aphids, flea beetles, spider mites, thrips and whiteflies.

You can get rid of any of these pests using a high quality chemical formulated control. You may also use a natural method, preferably horticultural oil or insecticide soap. Other pests, especially cutworms and hornworms, can be easily picked.

4. Lack Of Sunlight

One reason is less worrying, or at least not much to work on and that is inadequate sunlight. Keep in mind that chlorophyll, which makes plant leaves green, is processed by the interception of the sun. So just place your plants in an area where it gets more sun.


“Why are my tomato plant leaves turning yellow?” No more scratching of the head and arguing about this or that. It’s a simple gardening care strategy. As what you’ve learned from above, you only have to maintain basic and proper maintenance from watering to controlling pests.

So go ahead, start working on what must be fixed and keep your tomato plants healthy.

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