Why do tomato seedlings curl their leaves, reasons

Why do tomato leaves dry out and curl?

There are many reasons why the leaves of tomato seedlings curl. Often the problem is faced by inexperienced gardeners who make mistakes when caring for seedlings.

Twisting Down

If the leaves of tomato seedlings curl downward, this indicates the presence of the following factors:

Mechanical damage to the root system.
Damage by pathogenic microorganisms.
Irrigation technology violations.
Incorrect pinching.

Downward curling
An imbalance of nutrients in the soil may also be the cause.

Twisting up

Tomato foliage may curl upward under unfavorable climatic conditions, the presence of typical diseases or attack by pests. Excessive watering can also cause leaves to curl upward. The crop thus gets rid of excessive amounts of moisture in the soil.

Inside

The leaves of tomato seedlings curl inward due to insufficient watering. This is how the plant tries to retain life-giving moisture. It is recommended to spray the seedlings daily and provide moderate watering in the morning and evening hours.

Pests

Whiteflies, aphids and spider mites love seedlings and young tomato plants.

The whitefly settles on the lower leaves of tomatoes. Curling of the plates, their dryness, fragility and falling off is the third stage of the pest attack. It is preceded by the appearance of sticky whitish spots on the back of the leaf.
Aphids attack the upper leaves. Having settled on the seedlings, the insect introduces a substance into the plant tissue that causes curling of the leaf plates and deformation of the stem.
Spider mites cause the leaves to curl into a tube. In addition, the plant is covered with a thin cobweb.

Common Possible Causes

Among the main causes of leaf curling are the following:

absence or improper preparation of seeds or soil for planting;
lack or excess of nutrients in the soil;
drying out or excessive moisture of the substrate;
low humidity and too high room temperature;
insufficient amount of sunlight;
consequences of exposure to direct rays of the scorching sun;
infection or pest attack;
incorrectly selected container for seedlings;
the presence of serious mechanical damage during transplantation and pinching;
characteristics of the varietal variety.

The growth rate of veins is faster than the growth rate of the leaf itself

Leaf folding can occur if the leaf blade develops more slowly than the central veins. When examining the bush, you can see that the foliage on the entire plant is thin and curled down. This indicates the varietal characteristics of crop growth.

Features of growth

The variety of shapes and shades of tomatoes amazes even the most experienced gardener. The foliage of some varieties can be potato-shaped, carrot-shaped, or curved. There are varieties of tomatoes whose leaf blades curl like a ram's horn, even when the plant is in absolute health. These varieties include the hybrids Japanese crab, Honey Drop, Fatima, Oxhart, as well as vigorous crops and individual varieties of cherry tomatoes. In some varieties, when there is a sharp change in temperature, the upper leaves curl into a spiral, while the rest look normal.

Improper nutrition and nutrition

The main reason why foliage begins to dry out is an imbalance of nutrients in the soil. An improperly prepared substrate may have an acidic or alkaline environment, which is unacceptable for tomatoes and has a detrimental effect on seedlings. The seedlings look sickly, the brightness of the foliage disappears.

Improper nutrition and nutrition

The lack of useful elements has an immediate effect on the appearance of the plant. They begin to feed the seedlings on the 10th day after picking; complex mineral preparations are used for the procedure. Subsequent feedings are applied every 2 weeks. If the seedlings look weakened and the foliage begins to shrink, this indicates a lack of nitrogen. But yellowed seedlings and thickened leaf veins indicate its excess.

With a deficiency of manganese, calcium and boron, the leaves on top of the bush develop poorly. An insufficient amount of phosphorus gives the twisted plates a purple tint, and sometimes the bush begins to turn blue. If the foliage is yellow and drooping, curling at the tips, the plant is not receiving enough iron. A curly leaf blade indicates a lack of potassium.

Feeding seedlings with microfertilizers Sortvorin, Kristallon, Kemira Lux, Universal and Gumat +7 will help eliminate nutritional deficiencies. Good results are obtained by feeding seedlings with potassium sulfate, ash and other folk remedies.

High air temperature

For proper development at the initial stage, seedlings require a temperature regime of +15+17 during the day and +11+13 at night. Such indicators contribute to the hardening of seedlings and prevent stems from stretching in hot weather or in low light conditions. After 10-14 days, the temperature should be within +15+18 at night and +20+23 during the day.

When temperatures are too high, foliage begins to wrinkle and curl. The plate is rolled up into a tube or boat, which reduces the area of evaporation of life-giving moisture. In the late evening and at night, the leaves unfurl again and look healthy.

Improper watering

The top layer of the substrate in which the seedlings grow should be slightly moist. The soil should not dry out completely or be excessively wet. Young plants respond well to daily irrigation using a spray bottle. Watering is carried out as the soil dries, approximately once every 5-7 days. More frequent watering can cause the formation of superficial roots, which is detrimental to the main root system.

Improper watering

With a lack of moisture, the lower leaves of the tomato curl, turn yellow and wither. Damaged foliage cannot be restored and falls off. Excessive moisture provokes the development of a dangerous disease called blackleg, which is accompanied by rotting of the trunk of a delicate plant.

Presence of pests

Seedlings growing in a greenhouse can be attacked by spider mites, aphids and whiteflies. These pests multiply quite quickly. By feeding on plant sap, insects can cause irreparable damage to plantings.

Affected plants should be treated with modern drugs: Verticillin, Aktelik, Fitoverm.

Mechanical damage

The tomato is not afraid of transplantation and responds positively to picking, deepening and hilling. However, if the fibrous suction roots of tomato seedlings are damaged, the leaves curl. Seedlings may wither and lag behind in development, which further delays the date of fruiting. Proper watering and careful hilling will help correct the situation.

Failure to comply with watering standards

Pay attention to the tips of the leaves. If they curl upward, but there are no other manifestations on the leaf, then the plant is most likely overwatered. If the leaves curl down, then underwatering occurs.

You can check the soil moisture by slightly loosening it. If the soil crumbles at the same time, then it’s time for watering. Remember that in different phases of the growing season and depending on the planting location (open or protected ground), watering tomatoes varies.

So, before flowering begins, it is advisable to moisten the soil under the plants on average once a week, spending an average of 5 liters of water on each bush. During flowering, the volume of water is reduced to 2-3 liters per bush, but the tomatoes are watered twice a week. And during the period of fruit formation they return to the previous schedule.

How to properly water tomatoes in a greenhouse and open ground
We'll tell you how to water tomatoes and how to properly combine watering with fertilizing.

Watering in open ground differs from moistening protected by periodic irrigation: in greenhouses and greenhouses, tomatoes are watered much more often, dividing the volume into several procedures per week.

And for those who do not have the opportunity to visit their dacha often, there is an excellent alternative - drip irrigation or mulching (using agrofibre, spunbond, lutrasil, hay, compost, grass clippings, wood chips and sawdust) of the soil under the plants. Both methods help retain moisture in the soil.

A few ideas on how to make drip irrigation at your dacha with your own hands
A drip irrigation system can be purchased at the store. But making it with your own hands is not much more difficult and much more interesting, and sometimes much cheaper.
Everything you need to know about mulch, its types and effects
Caution: not all types of mulch are created equal!

Twisting as a symptom of the disease

Tomato seedlings often suffer from various diseases. The presence of infection is accompanied by changes in the standard appearance of the plant. Each disease has a different impact on culture and requires different treatment and prevention measures.

Blackleg

When kept in a stuffy, humid, poorly lit room, tomato seedlings are often affected by blackleg. The infection is caused by molds and bacterial rot, which are transmitted through untreated soil or contaminated seeds. Affected specimens do not survive, wither, and subsequently dry out. Pathogenic microorganisms infect the root system and base of the stem, thereby blocking the access of nutrients and moisture to the top.

Blackleg

There are no effective treatments for this disease. Particular attention should be paid to preventive measures. Soil, working tools, containers must undergo a mandatory disinfection procedure. It is important to organize regular ventilation and shading of the room. If seedlings are grown on a balcony or windowsill, it is important to provide shading during the period of active sun.

Bacteriosis

The carriers of this infection are insects that infect seeds and untreated planting material. Affected seedlings lag behind in development, young leaves lose color and may curl outward. The inflorescences lose their bright yellow tint and become whitish. The ovary is not formed. Sick specimens are subject to complete destruction, and the growth site is subject to disinfection.

Fusarium wilt

Soil microflora can become a source of dangerous fungal diseases. Fusarium wilt spreads throughout the plant from the bottom up. The lower leaves turn yellow first, and then the disease reaches the crown. Fighting the disease is pointless; the affected seedlings are destroyed, and the soil mixture is disinfected with a manganese solution.

Bacterial canker of tomato

A dangerous disease can affect a plant at any stage of development. Often the disease manifests itself at the stage of 2-3 true leaves. Pathogenic microorganisms can spread through soil, untreated tools and questionable seed material. Small whitish spots are noticeable on the plant, which subsequently begin to turn yellow, and the leaves of the tomato seedlings curl.

Bacterial canker of tomato

The disease affects the vascular system of the crop, causing tomatoes to wilt. No existing drug can fight bacterial cancer. Warming the seed before sowing will help prevent the development of the disease.

Thin leaf virus

The spread of infection is often caused by Dutch seeds that have not undergone antiviral treatment. Also, the disease can develop in the hot spring season when the seedlings are on a sunny window. The infection cannot be treated, and the affected plant does not produce fruit.

Yellow curl of tomato leaves

The viral disease is carried by whiteflies. In appearance, curliness can be confused with yellowness of the top, lack of magnesium, phosphorus and iron, as well as chlorosis. If the disease affects immature seedlings, the specimens develop poorly and do not produce an ovary. The diseased plant begins to bush, the leaves turn yellow and curl. Affected tomatoes must be removed from the garden.

Violation of agricultural technology

Stepsoning

As the tomato bushes grow, side shoots, or stepsons, begin to grow. They must be removed promptly. If this is not done, the bushes will become too branchy and the leaves will not have enough nutrients, causing them to become smaller and curl downward.

There is also a downside to this situation: if you remove many stepsons at once, the plant will react to this by twisting the leaves into a tube and dropping buds.

Transfer

Tomatoes always react to transplantation by losing turgor and curling the edges of the leaves downwards. This condition is considered normal for 2-3 days. If it is more, then we can talk about stress and the addition of a fungal infection.

Treatment methods

The answer to the question of what to do if the leaves of tomato seedlings curl depends on the cause of the development of the disease. Initially, it is necessary to regulate the irrigation regime and room temperature. In a private house or apartment, it is recommended to reduce the power of the batteries, cover the heating device with a warm blanket, or place containers with seedlings far enough from the heat source. Provide entrances with sufficient sunlight and protection from direct rays. As a rule, these measures are sufficient to restore the health of the seedlings.

Tomatoes, like peppers, react poorly to dry air. If the room humidity is low, you should use a humidifier or spray the plants with a spray bottle using water at room temperature. If seedlings are affected by viral diseases, all diseased specimens are immediately removed, and the remaining plantings are treated with special compounds. If pests are detected, they are treated with insecticides.

Curling of the upper leaves

The main reason for the curling of the upper leaves of tomato seedlings is an excess of nitrogen. This crop takes feeding well, but most of all it needs potassium and phosphorus. Nitrogenous fertilizers lead to fattening: the stem thickens, the leaf blades increase, and the apical leaves begin to curl into a ring.

The tops of greenhouse tomatoes often begin to twist when the temperature in the greenhouse exceeds the critical +30...+35°C.

How to avoid curling

It is not enough to know the reasons why the leaves of tomato seedlings curl. It is important to be able to prevent deviation. Preventive measures are as follows:

Treating seeds before sowing

Treating containers for planting with disinfectant solutions. Often, gardeners use a medium concentration manganese solution.
Proper soil preparation. Purchased or prepared substrate is spilled with Fitosporin or potassium permanganate. It is also important to add sand, ash and vermiculite to the soil. With the help of these components, the soil mixture will be light and loose, which is positive for the development of seedlings.
Treating seeds before sowing. For the procedure, a strong solution of potassium permanganate, fungicides and alcohol-based preparations are used.
Using a disinfected tool when picking seedlings.
Compliance with the recommended temperature regime at different stages of seedling development.
Organization of good drainage and systematic watering. Stagnation of water will provoke root rot, and insufficient moisture disrupts the development of the root system.
Use of nutritional supplements at the specified times and in the recommended quantities. An excess of minerals also has a detrimental effect on seedlings, as does their deficiency.

The health of seedlings is influenced by many factors. To get strong, viable seedlings, you need to gain experience and be patient. Providing proper care and compliance with cultivation requirements will avoid most problems with tomatoes. If curling does begin, treatment should be started immediately, otherwise the risk of crop loss increases.

Advice from gardeners and vegetable gardeners

Gardeners and gardeners use folk remedies to feed tomato seedlings or treat them against pests and diseases. They act effectively, and at the same time are safer and non-toxic. Several recipes:

For the prevention and destruction of pests, it is worth using onion infusion. You will need to chop 200 g of vegetable, pour 10 liters of water into it. Leave for 12 hours and use for spraying.
To protect seedlings from diseases, chop 100 g of garlic and dilute the resulting mass in 10 liters of water. After 3-4 hours, strain the solution and process the above-ground part of the tomatoes.
To feed the seedlings after picking, you will need to prepare an infusion of onion peels. For this, 2 tbsp. l. raw materials pour 2 liters of hot water. Leave for 24 hours in a warm place, strain and use for watering.

Varietal feature

Some tomato varieties curl their leaves not because of some disease, pest or lack of element in the soil, but because this is their biological feature. The leaves curl to the greatest extent in the following varieties: “Fatima”, “Honey Drop”, as well as in the vast majority of cherry tomato cultivars.

Conclusion. When curled leaves appear on tomato plants, do not immediately reach for chemicals or fertilizers; first assess the conditions in which your plants are located. It often happens that they simply do not have enough moisture or, on the contrary, there is too much of it. Water if the soil is very dry, or stop it if there is excess moisture; carry out pinching, and only if all this does not help, try to apply fertilizers or carry out pest or disease control according to the schemes that we have described.

If you have any questions, we will be happy to answer them in the comments.