White Lines on Tomato Leaves – What Causes & How to Control?

Most new gardeners wonder about the white lines on tomato plant leaves. These lines are nothing but dead tissues of plant leaves left behind by larvae.

Tuta absoluta is a common pest that attacks tomato plant and lays eggs between upper and lower surface of leaves. Newly hatched larvae feed on plant tissues and leave white tunnel like lines on plant leaves.

Though it won’t kill tomato plant, leaf miners results in unattractive fruit and reduce yield.

Removing or pinching off the affected tomato leaves is one of the easy ways to get rid of these pests.

Tomatoes are one of the most common plants grown in the garden, but sadly tomatoes as a plant are also supremely sensitive to cold and sun.

Tomatoes can grow in any season, which is why people start by planting them indoors and then transplanting the plant to outside when the temperatures are okay, and the soil has turned warm.

This transplant is one primary reason behind the issue of white lines on tomato leaves as the plant can get messed up because of temperature and light extremities as it is a supremely vulnerable plant.

To understand it clearly, let us understand what causes white lines on tomato plants thoroughly.

What Causes White Lines on Tomato Plant Leaves?

white lines on tomato leaves

If suddenly one morning you find a silver or white leaf colour on your tomato plants, it is either because of the sun’s damage, cold or even a disease (fungal).

One primary reason behind white lines on tomato leaves, especially in the young seeds transplanted from one place to another, is that they are exposed to an intense amount of sunlight.

Keep in mind that tomatoes require a considerable amount of sun rays to grow healthy, but a change to too a sudden one can shock the plant and cause it to turn its leaves white.

The damage caused to the leaves by the sunlight gives a look of the white colour border on leave, but the leaves may also break and curl and leave just a little amount of foliage behind. One more reason that can aggravate white lines on tomato leaves is the winds.

On the other hand, the mature tomato plants can also suffer from sunscald those results in papered or blistered fruits.

How to Get Rid of White Lines on Tomato Plant Leaves?

The solution of not having white lines on tomato plants caused by sun exposure is super simple when you are transplanting the plant, let the tomato plant languish in the shade for some time, and then move the plant outside when there is an overcast.

Then start exposing the plant to the sun for a few hours every day for about two weeks and then move it completely. This process is known as hardening off; it will allow the plant to acclimate to the environment and get used to the sunlight.

If you live in an area where there is an issue of hot and dry winds, try placing a windbreaker around the plants or relocating them to a protected area.

If you don’t have either of the windburn or sun scorch issues, then the plant will recover, and you can easily remove the leaves that are damaged or afflicted.

Check this out: My Tomato Seedlings Stopped Growing?

1. Fungal reasons behind white lines on tomato leaves

The fungal reason behind the tomato leaves getting white lines is actually the same: overwatering. Overwatering can stimulate the fungal spores, which will make the root to rot or cause Septoria leaf spots or Alternaria.

So while transplanting the plants, make sure that you are watering the transplanted plants deeply for the first three days, and then water them regularly as per your climate.

  • Watering deeply for the first three days will help in-depth root development and deterring away from the fungal spores. If the Fungal disease still erupts by any chance, use a suitable fungicide that is specially made for tomatoes plants so that it can repair it.
  • The deficiency of nutrients that leads to tomatoes leaves turning white.
  • Another reason as to why your leaves would be turning white is that the tomato plant doesn’t have the amount of nutrients it needs.
  • Tomato plants that have a deficiency of nitrogen/phosphorous or both will start showing whitening symptoms or the yellowing of leaves. So, in order to get rid of these spots, make sure that you are feeding an ample amount of nutrients to your plant.

On the other hand, deficiency of calcium or magnesium can also cause whitening of leaves, and in this case, the veins retain the green colour. In this case, you need to use proper fertilizers or use garden lime, which will help increase calcium deficiency.

Also Read: Why are bottom of Tomatoes Turning Black Blossom End Rot?

2. Tomato Leaf Miners

Leaf miners are main cause reason why the surface of your tomato leaf is affected.

Leaf mining flies are one of the common pests found on tomato plants, leaf miners are small yellowed and black coloured flies that lay their eggs on the tomato leaves, and once the larvae start to hatch, they start consuming the cells of the leaves. 

Once they are done, they move towards the leaves’ edge and then drop to the ground and start pupating. The larvae that are pupating become the easy target for the biological controls; pesticides can also destroy them.

You can also remove them by doing the mentioned below steps.

  • Always remove the pruners and the other isolated leaves with the newly formed ones so that you can stop the miner infestation before it turns serious. Always monitor your plants closely, and if you find miners, one leaf (one to three or more in number), use insecticides.
  • If your tomato plant is affected, start by placing plastic trays beneath the plants and check them continuously and keep track of the leaf miner’s pupae. If you find one or two, you can kill them by hand, but if they are more in number than continuously, apply an insecticide.
  • Apply Spinosad to organically grown crops as a drench on the soil under the tomato foliage. Using the plastic trays, continue to check for new pupae and reapply Spinosad every seven to 10 days until little or no pupae appear.
  • The plants produced with the help of the traditional chemical way start using cyromazine and abamectin rotationally. Start by applying abamectin first, and then after two to three weeks, apply the cyromazine.
  • Use this to rotationally through the entire season and give a break of two to three weeks between each application. Repeat this till the leaf miners disappear.

Check this: How to Use Epsom Salt for Tomato Plant?

You can also minimize the miner’s population for the next year by immediately plowing the plants that are under spent. Moreover, you need to rototill the garden until all the pupae are buried deep inside.

For doing all the steps as mentioned earlier, you need the following things like

  • Rototill
  • Bypass pruners
  • Plastic trays which are 12 inches wide and 15 inches long
  • Cyromazine
  • Spinosad
  • Abamectin
  • Fair warning!

Keep in mind that over the years, these miners have become resistant to a lot of pesticides like Pyrethroids, organophosphates, carbamates, etc. so make sure you are carefully using the pesticides, as at times, they will kill the insects that keeps the larvae under the check.

Here are some tips to keep in mind while growing your tomatoes, so you don’t encounter the problem of white lines on tomato leaves.

Growing tomato plants is a very fruitful task, especially if you have just started your vegetable garden. Every tomato loves wished to grow the ultimate form of tomato, firm, juicy, a mixture of sweet and tangy, blemishes free and lastly aromatic.

Though it may be fruitful, growing tomatoes can be difficult as they are prone to infestation.

One major trick for growing great tomatoes is choosing the best varieties, and also some things like starting the growth properly and controlling all the issues before they occur. Here are some tried and tested growing tricks and tips which make sure that your tomatoes are healthy and juicy.

Also Read: How to Get Rid of Aphids and Flea Beetles?

3. Never crowd the tomato seedling

If you plan to grow the tomatoes from seeds, always provide it a lot of room so that it branches out. In other words, you need to thin down the seedlings into one strong plant and put it in a small pot or distribute them evenly.

Find out which seedling is strong and snip out the weaker one to have the best grower. Keep in mind that the larger the crowd, the shredded the plants will be, and the more they are prone to diseases. 

Then transplant the seedlings into 4-inch pots immediately after they get their first set of the true leaves.

Make sure that plants are getting lots and lots of light.

Tomato seedlings require a lot of strong and direct lights. If you live in winter region areas, either grow them in the greenhouse or use an artificial source of plant lighting and keep the light switched on for around 14 to 18 hours daily.

To ensure that the plants are growing stocky and not in any spindly manner, keep the baby plants a few inches away from the fluorescent lights. You will have to raise the lights when the seedlings are growing.

And once they are ready to plant them outside, make sure that you keep them in the area that receives the highest amount of light.

To ensure the tomato plants grow stocky, not spindly, keep the young plants only a couple of inches from fluorescent grow lights.1 You will need to raise the lights (or lower the plants) as the seedlings grow. When you’re ready to plant them outside, choose the sunniest part of your vegetable garden as their location.

Either use a fan or keep them in the area which receives a lot of wind.

To be strong, the tomato plants need to move a lot and also sway in the breeze so that the stems can be strong. This usually happens naturally, especially in the outdoors.

But, if you are growing the plants indoors, you will have to provide them with air circulation; you can either o this by using a fan for 10 minutes twice daily or make some sort of crosswind situation with makeshift windows.

You can also ruffle them, in the same manner, you ruffle a baby’s head that is gently for a few minutes but this needs to be done several times a day. Though this a tedious job, if you have no other option, you can use this.

Check this: Why Are Eggshells Good for Tomato Plants?

4. Try to preheat the garden, Soil

As stated earlier, tomatoes love a lot of heat, which is why they will not grow until or unless the air and the Soil are warm. So before you put in the seeds, you can cover the Soil with either black or red plastic sheets to remain warm.

The warmth will speed up the process of tomato growth. You can either remove the plastic before planting or use the red plastic even after the planting is done, as it will increase your tomato yield.

5. Bury the stem properly

Always plant your tomatoes deeply. That is, only a few of the leaves should be visible. This is a great way since tomatoes will be developing the roots and their stems, which will strengthen the plant.

You can also dig a deep hole or dig a very shallow trench so that the plants lay sideways. This will help the plant straighten up itself, and the growth will be in the sun’s direction. Just make sure that the tomatoes stake or the cage is not being buried into the stem.

6. Once the soil is warm, mulch the tomatoes

If you have kept the red/ black plastic sheet, it’s okay. If you haven’t, then wait for the ground to warm up completely. Though mulching is known for conserving the water and preventing the soil and soil-borne diseases from eating the plant, if it is done way too early, it will cool down the soil and throw shade on it.

Now that you know tomatoes are known for their heat, allowing the soil to warm up will help the plant spring up.

Once you have realized that the soil’s temperature, the environment has started to remain warm throughout the day, add a layer of mulch so that it can start to retain its moisture.

7. Always remove the bottom leaves

Once your plant has reached a height of 3 feet, you should remove the leaves from the plant’s bottom.

Since they are the older leaves, they will develop issues like fungal infections. This happens because the lower leaves end up getting low amount of sun and airflow, and these leaves are closest to the ground. They will be the first place where all sorts of pathogens can attack them.

If you remove these leaves, you will save the plant from fungal diseases. You can also spray compost tea etc. so that the fungal diseases can stay away.

Also Read: Do Tomato Seeds Need Light to Germinate?


Larvae feed on inner plant tissues leaving dead tissues behind, which look as white tunnels on tomato leaves.

White lines on plant leaves are enough to confirm this issue. To get rid, removing infected leaves is the simplest way.

If you flip the leaf, you’ll notice eggs behind it. Remove them, so that you can halt further feeding of leaf miners.