Why do tomato seedlings' leaves wither and curl and what to do?

What to do if the leaves of tomato seedlings wither and curl. The first step is to find out whether curling is a varietal feature, to figure out what was done wrong when planting seeds or while caring for seedlings.

About the causes of leaf curling

There are several reasons why all the leaves of tomato seedlings curl. All of them can be combined into groups:

• diseases of fungal, viral, bacterial nature;
• pest invasion;
• poor agricultural technology;
• feature of the variety.

There is no need to give up; it is better to start eliminating the causes in time. To do this, it is urgent to find out why the leaves of tomato seedlings curl.

Tomato diseases and leaf curl

Very often, infection becomes the reason why the leaves of seedlings or adult tomatoes curl. Infections can be of different nature: viral, bacterial, fungal.

Stolbur

Signs of the disease are changes in leaf color and deformation of leaves located at the tops of the central and lateral shoots. They take on a purple or pink-violet hue. The maximum effect in the fight against disease can be achieved by treating diseased plants with Phytoplasmin.

Bacterial cancer

Deformed leaves that have lost their usual shape are found in tomatoes with bacterial cancer. It is useless to treat plants. It is necessary to get rid of diseased seedlings (bushes) as quickly as possible and destroy them. Treat healthy seedlings with a solution of copper sulfate for prevention.

What insects cause tomato leaves to curl?

Sometimes you can easily understand the problem of curled leaves by taking a close look at the back of the leaves and the stems. Insect flukes that settle on seedlings suck the sap and damage the surface of the stems and leaf blades. Aphids, whiteflies, and spider mites help the leaves curl.

Aphid

A picture familiar to many: a chain of ants crawling along a trunk, and the tops of tomato bushes with curling leaves. When you see it, it immediately becomes clear that aphids have settled on the tomatoes in the greenhouse. You need to get rid of not only aphids, but also ants. The ground under the bushes can be sprinkled with shag or red pepper to prevent ants.While there are no tomatoes on the bushes, treat the entire surface of diseased plants with an insecticide; the following are suitable for this purpose:

• Aktara;
• Spark;
• Proteus.

It is more difficult to decide what to do if there are already tomatoes hanging on the bushes. In this case, it is better to use folk remedies for aphids. Infuse wormwood or celandine. In the evening, treat plants infected with aphids with infusion. To make the solution stick to the surface, add grated laundry soap to it. For 3 liters of water you need 500 g of wormwood, celandine for the same volume you need 2 times less.

Whitefly

The reason why the leaves of tomatoes curl in a greenhouse may be a whitefly butterfly; it is quite difficult to find it, since during the day it hides in the lower part of the tomato bush. To prevent whiteflies, tomatoes should be sprayed with an infusion of yarrow, so that you don’t have to wonder why the tomatoes’ leaves are curling. For 5 liters of infusion you need 150 g of chopped herbs. Be sure to add 100 g of laundry soap to the infusion.

Spider mite

The obvious presence of spider mites on tomatoes is indicated by external signs: there are cobwebs on the branches, the leaves are curled. Due to the fact that mites actively suck the sap, the leaves dry out and the fruit set is worse. If there is at least a month before harvest, you can use chemicals:

• Borneo;
• Flumite;
• Oberon.

For ardent opponents of chemistry, we can recommend infusions of dandelion, green onions or garlic. For 3 liters of infusion you need 0.5 kg of dandelion flowers. The same proportions if you decide to make the infusion from onion feathers. To prepare garlic water you need 15 cloves.

Problems with agricultural technology

Basic care for seedlings and adult tomatoes consists of watering, fertilizing, and creating a certain microclimate (temperature, humidity, lighting). Curled leaves are a sign that care is poor.

Soil moisture

The main reason why tomato bushes are partially deformed is soil moisture. In this case, it does not matter at all whether there is an excess or lack of moisture in the soil; in both cases, the leaves curl, but in different ways.

When the soil is too dry, the leaves curl downward; when there is excess moisture, the edges bend upward.

Most often, beginner gardeners have problems with watering. Experienced gardeners know all about the dangers of frequent, shallow watering. By soaking only the surface layer (5 cm) when watering, the gardener practically deprives the plant of moisture, since the bulk of the roots are located deeper. Due to lack of moisture, the plant lowers its leaves.

The problem is easily solved. The gardener must reconsider the watering scheme. Water in open ground once a week; in a greenhouse, water thoroughly every three days. Two buckets of water is the approximate volume of water for an adult tomato plant. It is better to water early in the morning.

If the seedlings are watered incorrectly, the same problems arise. To prevent the seedlings from dying, they urgently need help. Stop watering when the soil becomes waterlogged, and resume watering after the top layer of soil up to 5 mm thick dries out. If the soil is dry, water the seedlings with water at room temperature and slightly humidify the air in the room using a sprinkler or household humidifier.

Temperature

In summer, it’s easy to understand why the leaves of tomatoes in a greenhouse curl. At noon, the air temperature in a polycarbonate greenhouse can exceed the threshold of 35 °C. In this case, the outside air temperature may not exceed 25 °C. It's all about the sun, it warms the air in the greenhouse.

Tomato bushes suffer from the heat; the leaves begin to curl due to temperature and loss of moisture.

In hot weather, irrigation by sprinkling is strictly prohibited. This applies to any time of the day. When watering by sprinkling in the morning and evening, late blight may break out, and watering during the day will lead to sunburn. Tomato leaf curling in a greenhouse can be stopped by watering at the root. The most ideal option for both tomatoes and the gardener himself is a drip irrigation system in a greenhouse.

In hot weather, you can try to reduce the evaporation of moisture from the surface of the plants and from the soil; to do this, protect the tomato bushes from the sun. For shading, a white covering material is used, and the upper part of the polycarbonate greenhouse is whitened. A natural or automatic ventilation system reduces the air temperature inside the greenhouse.

Soil for seedlings

Poor soil is one of the reasons why tomato seedlings have curled leaves. Using garden soil is a common mistake gardeners make. Garden soil may contain pathogens; in addition, due to intensive use, it may not contain the microelements necessary for seedlings. The lack of useful elements in the soil is manifested in the appearance of the seedlings.

With a lack of phosphorus, the leaves of the seedlings change color from green to gray-green, and they curl up.

To return the plants to their normal appearance, they need to be watered with a solution of superphosphate or a solution of any complex fertilizer containing phosphorus.

If the color of the tomato bush acquires a slight purple tint, and the leaf blade bends inward, this is a signal that there is a lot of zinc in the soil. Excess copper in the soil causes all the foliage to curl and the color to become bright green.Weakened seedlings should be transplanted into high-quality soil, and a week after transplantation they should be fed with complex fertilizer for tomatoes.

The problem is fertilizers

Applying fertilizers without a system leads to the leaves of seedlings and adult tomato bushes curling. Moreover, seedlings spin both when there is a lack of fertilizer in the soil and when there is an excess of it.

Excess nitrogen in the soil

Gardeners try to stimulate seedlings that are lagging in growth with a heavy dose of fertilizers containing nitrogen. If there is an excess of nitrogen in the soil, seedlings absorb phosphorus and potassium and other microelements worse. Lack of nutrition affects the condition of the leaves, their color changes, and they begin to curl.

Gardeners often upset the nitrogen balance in the soil by introducing nitrogen-containing fertilizers in excess of the norm: ammonium nitrate, urea, and also use infusions of mullein or grass. Not taking into account that liquid infusions of mullein and herbs also contain nitrogen.

Having understood why the upper leaves of tomato seedlings curl, you need to increase the content of phosphorus and potassium in the soil, thereby neutralizing nitrogen. Seedlings can be fed with an infusion of ash, and adult tomatoes can be fed with potassium sulfate (10 g/m²) to prevent the leaves from curling; in addition, water all the tomatoes with a superphosphate solution.

Features of the variety and leaf curl

Some varieties (usually indents) stand out due to their appearance. Their leaf blades are narrow, not branched, and the tips of the leaves bend downwards. Compared to other tomato bushes (seedlings), such plants look painful, but in this case the gardener does not need to worry about the fate of the future harvest.

The leaves of tomato seedlings curl due to a genetic feature.In this case, adult plants and seedlings are absolutely healthy and no measures need to be taken. This feature is found in tall Cherry tomatoes; in addition, the leaves of the following varieties can be wrapped:

• Honey drop;
• Fatima;
• Japanese crab.

Conclusion

The appearance of deformed leaves on seedlings (tomato bushes) should not cause panic among novice gardeners. In most cases this happens for the simplest reasons. First of all, create normal conditions for plants to grow, resort to chemicals in the most extreme cases and they will not grow.