Skip to Content

White Lines on Tomato Leaves — Worrying or Not?

White Lines on Tomato Leaves — Worrying or Not?

Sharing is caring!

Tomatoes are popular garden plants that are suitable for both outdoor and indoor gardening.

They grow in any season; hence many gardeners and homeowners plant them indoors and later transplant them outside where temperatures are more favorable and the soil has warmed up.

However, tomato plants are very sensitive to sun and cold, and as they get transplanted, the plants are damaged by light and temperature extremities.


White Lines on Tomato Leaves

Tomato plants are extremely vulnerable to extreme temperatures and light conditions, tending to develop white lines as a result. It could be caused by a cold, fungal disease, or sun damage. The problem is common, especially for young plants, as they get exposed to intense sunlight during transplanting. 


Why Tomatoes Have White Lines

Most home gardeners take delight in having lawns and backyards filled with healthy, plush green plants that bear delicious vegetables and fruits at the end of the season. 

Tomatoes are perfect for growing in home gardens, and they don’t take up much space, so they are ideal for even the smallest lawns and balconies.

In addition to the many health benefits, tomatoes add a surplus of flavors to recipes and are also delicious when eaten raw. As a home gardener, you are constantly worried about the various threats your tomato plants face.

Regardless of how much care you give your plants, they can easily be attacked by pests and diseases, which affect the quality of produce.

If you cultivate tomatoes, you know their susceptibility to diseases, with white lines on leaves being prevalent.


What Causes White Lines On Tomatoes

Homegrown tomatoes are rich in taste compared to commercial ones, mostly bred for their size and firmness.

Every home gardener wants to grow juicy, squishy, sweet, and perfectly firm tomatoes, so if you notice white lines, it could be caused by any of the following.


Environmental Exposure

Most tomatoes affected by white lines are those recently exposed to intense sunlight. When tomato seedlings are young, they are vulnerable to changes in the environment.

These plants require transplanting, so when their venue is altered, they are shocked, causing the leaves to whiten.

The damage is characterized by a white border of leaf color on the plant, and subsequently, the leaves curl and break, reducing the foliage on tomato plants.

To control this problem, it’s crucial to allow young plants to languish in shady environments for some days, then take them outside when it’s cloudy before permanent transplantation.

The plants should then be placed in the sun for some hours every day over a week or two to harden them off and allow them time to acclimate to more radical environs when transplanted outdoors.

If the plants are windy, the transplantation aggravates the condition, affecting tomato health and yield. Mature tomatoes affected by sunscald produce papery or blistered fruits.

Hot, dry winds worsen the conditions, so when transplanting, place a windbreak around the plants or move them to a protected area.

Plants affected by windburn and sun scorch recover easily as long as you get rid of the plagued leaves to stop the spread of disease.


Nutrient Deficiency

Tomatoes require surplus nutrients for healthy growth and development; otherwise, they develop health issues.

Plants that lack phosphorus or nitrogen show yellowing or whitening on leaves, and those with magnesium and calcium deficits also cause leaf whitening, but their leaves retain the green hue.

Tomato fertilizers have sufficient amounts of nutrients to supplement the deficiency and fix leaf whitening.


Fungal Diseases

Tomato plants may develop white lines on the leaves due to fungal diseases, which result from overwatering the plants in most cases.

When there is too much water in the soil and poor drainage, the excess moisture stimulates fungal spores, which cause root rot or leaf spot in the form of white marks on leaves.

It’s important to understand the irrigation schedules of young and mature tomato plants to avoid excess irrigation.

After transplanting, these plants should be watered deeply in the first three days, then every week, depending on the climate. This aids in deep root development and discourages the formation of fungal spores.

Tomato plant’s fungicides are effective in repairing white leaf damage.


Leaf Miners

Tomatoes have a long growing season which makes them prone to various types of diseases and infestations. If you notice white squiggly lines on the leaves, your plants could be infected by leaf miners.

Leaf miners don’t pose a big threat to plants if handled on time and efficiently, but if ignored for a while, they could be detrimental to the quality of your harvest.

Leaf miners eat along the lines, through the leaf, and in some cases, they leave small spots on leaf surfaces.

In case the infestation is extensive, leaf miners open pores on leaves which allow in bacteria and fungus, causing graver issues to the plant.

It’s hard to rid of these pests, and they affect the general health of your plants.

With progressive leaf damage, the plant cannot convert light to energy which causes stunted plant growth.

Failure to manage the infestation affects the tomato yield and size, as when the affected leaves drop off, they leave the tomato fruits exposed and susceptible to sun scorch.


Frequently Asked Questions about White Lines on Tomato Leaves


How can I control leaf miner pests?

Leaf miners cause substantial damage to tomatoes if left unmanaged. The best control against these pests is the use of pesticides on the infected plant. Spray at the right time to ensure the pesticide reaches the leaf miner larvae. Alternatively, use beneficial bugs that are natural predators of leaf miners or use insecticidal neem oil to infringe on the life cycle of leaf miners.


Can we eat tomatoes from plants with white leaves?

These tomatoes are completely safe to consume. Leaf miners cause superficial damage to tomatoes because the leaves are not harvested or eaten. Most of the damage caused by leaf miners to tomatoes is simply ornamental, but if you don’t take precautions on time, these pests can ruin your garden.


Do leaf miners cause any damage to tomato plants?

Leaf miners are common bugs affecting tomato plants and causing severe damage to crop yield. Heavy infestations cause leaf drop and leaf scorch, and although there isn’t any direct damage on tomatoes, the leaf tissues that facilitate photosynthesis are damaged when leaves are eaten up.



If you are worried about white lines on your tomato plants, it’s crucial to understand what causes them to prevent the problem before it advances.

These plants have a high nutrition value, hence their popularity for home gardening.

These plants will give you a bountiful harvest even without constant attention, and their fruits are very versatile in the kitchen.