The leaves of tomato seedlings curl: up, in, down

Common causes of leaf curling

Incorrectly selected soil.
Skipping the stage of seed disinfection before sowing.
Excess or lack of moisture.
Low indoor air humidity.
Growing at elevated temperatures.
Burn of leaf plates.
Lack of lighting.
Diseases as a consequence of violation of the rules of agricultural technology.
Pest attack.
Mechanical damage during picking, pinching, transplanting.

Curling leaves of tomatoes of the Honey Drop, Fatima, Japanese crab, and certain types of cherry tomatoes can be considered the norm.

What to do, how to help tomato seedlings

You can help tomato bushes if you check them in a timely manner and feed them with useful fertilizers. Curled sheets are very different from the rest.

You can start caring for and preventing diseases at the stage of preparing seeds and soil. If you carefully prepare for sowing and check everything, then the appearance of curled leaves is excluded. A stable watering schedule with warm water is very important, and timing must be respected.

Many gardeners do not trust industrial disinfection of seeds and do it themselves. Plus, this procedure is also carried out with soil. This way the bushes grow much faster, and the fruits ripen large, juicy and tasty. You can set a special schedule for fertilizing the soil, which will have a beneficial effect on the further development of tomatoes. When landing, it is important to remember the distance.

The leaves are spinning down

Imbalance of microelements in the soil

The foliage of tomato seedlings may curl downward due to an imbalance of elements.

Copper. The lack of this element causes the tips of the leaves and their petioles to droop down. As the situation worsens, tissue necrosis or chlorosis begins.
Bor. If there is not enough of this element in the soil, then the young leaves of the upper tier begin to curl. A secondary symptom is yellowing of the middle layer.
Sulfur. Young foliage also suffers, with the subsequent formation of necrotic spots on it.
Potassium. It is considered the main element for this culture. With its deficiency, the tips curl down, then the plates begin to spin along the entire edge towards the central vein. A secondary symptom is small young leaves.
Zinc. A deficiency is fraught not only with outward curling, but also with the appearance of brown-gray spots on already formed leaves and yellow spots on young ones.
Nitrogen. The edges of the leaves not only curl down, but also quickly turn pale, gradually becoming completely yellow.

Both a deficiency and an excess of certain elements are harmful to plants.

Bor. The tips of the leaves dry out, become brittle and gradually bend down. Defeat comes from the bottom up.
Zinc. Under the gun - the lower, old foliage. Curl around the entire edge. A secondary symptom is a purple tint on the back of the plates.

Lack of moisture

The older the seedlings, the more moisture they need. Lack of water causes the leaves to curl outward. Defeat comes from the bottom up. A secondary symptom is that the leaves wither.

If in open ground adult plants, due to their long and powerful root system, can absorb water from the deep layers of the soil, then seedlings only form roots and therefore need frequent watering.

The situation is aggravated by growing seedlings in light, loose soil, which causes water to evaporate from the soil very quickly.

Correcting the watering regime will help prevent the problem. On average, this is once every 4-5 days in sunny weather and once every 7-8 days in cloudy weather.

A characteristic sign of lack of moisture is that the leaves not only curl downwards, but also become curly.

Curling of tomato leaves due to lack of moisture is typical for hybrids and varieties with thin leaf blades, which leads to rapid evaporation of moisture.

The leaves are spinning up

Imbalance of microelements in the soil

Magnesium. The lack of this element in the soil leads to disruption of the turgor of leaf plates and curling of their edges upward towards the central vein. An additional sign is chaotic yellow spots.
Potassium. The folding of leaves up into a tube with the simultaneous appearance of a brown border is the main sign of a lack of this element.
Calcium. With a lack of calcium, the leaf blades gradually curl their edges upward towards the midrib. Later, blossom end rot can be diagnosed on the plant.
Phosphorus. The lack of an element leads to the leaves curling upward and at the same time the plates on the lower side acquire a purple tint.
Molybdenum. The consumption of the element is insignificant, but if the soil is unbalanced, its lack leads to the edges of the lower leaf plates turning upward and yellow mottling appearing on them.

Excess moisture

Overwatering is very harmful to tomato seedlings. Curling of seedling leaves upward is the first sign of a violation of the watering regime. If the moisture balance is not equalized, not only the upper part of the plant will suffer, but also its roots, which will lead to rot and complete death of the seedlings.

Curling the leaves upward is a protective reaction of the plant. This increases the area of free evaporation.

It is recommended to water the seedlings no more than once a week. If there are problems, watering is completely removed until the top layer of soil dries. If mulch has been laid, it is removed and the ground is loosened.

Elevated temperatures

Regardless of where tomato seedlings are grown, in a room or a greenhouse, the temperature regime must be observed. If the thermometer in the room rises to +25...+27°C, then the plants, especially seedlings, turn on a defense mechanism.

The edges of the seedlings' leaves will first rise upward, and then the leaf blade will curl into a tube. This prevents the evaporation of moisture from the fabrics. A secondary symptom is dropping of the ovaries.

If it is impossible to lower the temperature, then it is necessary to humidify the air around the tomato seedlings, making sure that drops do not fall on the plants. In a greenhouse, daily ventilation is mandatory.

Tips for gardeners

If curling of tomato leaves is not a varietal feature, then you should follow a number of tips for caring for tomato seedlings.

Important:

do not try to “feed” the seedlings with all available fertilizers;
do not overdo it with watering, but also do not allow it to dry out;
gradually harden the seedlings to increase their immunity;
use plant protection products for preventive and therapeutic purposes.

Whatever the reason for the curling of tomato leaves, you should pay special attention to it. Do not panic and throw away all the plants; it is important to assess the condition of the seedlings and take all measures to improve their condition.

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.

Treatment and prevention, what you can spray with

When faced with the problem of curling, the first thing that comes to mind is: what can you spray to prevent the spread and cure it.

The lack of minerals can be overcome by fertilizing tomatoes with humus, ash, potassium monophosphate and copper sulfate. A weak solution of urea or Mortar often helps: 1-2 tablespoons per standard bucket volume.

Spraying with growth stimulants also helps prevent curling. The juicy taste of ripe tomatoes will subsequently become a pleasant bonus. Safe substances are suitable for this, such as: Energen, Zircon, Succinic acid, Senior tomato, Pennant.

Young, newly planted plants are more susceptible to diseases and pests. They can develop immunity by spraying them with an insecticide (Aatara, Biotlina and Fufalona).

If the cause of the disease is a fungus, a fungicide will help in the fight against it. It is better to give preference to well-known and proven drugs, such as topaz (dilute 2 milliliters of the substance per bucket of water), ordan (6.5-7.5 grams per 4-7 liters of water).

As the long-term practice of experienced gardeners shows, there are many reasons for the leaves of tomato seedlings to curl. Each has its own pathogen and methods of combating.

If you want to grow a high-quality crop, it is important to monitor the condition of the seedlings, establish a watering regime, ventilate the greenhouses, feed them in a timely manner, and get rid of pests, fungal diseases and viral pathologies. By following simple rules, the question will no longer arise: why do the leaves of tomato seedlings curl?

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.

Diseases

Violation of agricultural practices when growing tomato seedlings causes fungal and bacterial diseases. The pathogen can be identified by external signs.

Bacteriosis. The reason is the sowing of undisinfected seeds. Signs - young plants lose turgor, their leaves become smaller, the lower leaf plates curl outward.
Fusarium. A fungal disease that attacks the plant from the bottom up. There is a sharp loss of turgor, the edges of the leaves dry out and curl up.
Bacterial cancer. Develops at elevated temperatures and high humidity conditions. The leaves only spin upwards. An additional feature is dark bundles of veins on the cut of the petioles.
Stolbur, or phytoplasmosis. A disease carried by cicadas and bedbugs. Symptom: yellowing and deformation of leaf blades. The leaves along the edges acquire a violet-lilac hue, dry and rise upward, gradually the entire plate takes the shape of a boat.
Verticillium. A characteristic feature is yellow leaves below and chlorotic curl at the top. The leaves turn very strongly and dry out.
Tobacco mosaic virus. The main symptom is discoloration and wrinkling of leaves. The plates gradually curl and take on a fern-like shape.

Diseases

Adult plants and seedlings may be lost due to various infections. The appearance of an infection can be determined by the rapid development of negative changes in the appearance of plants. It is easy to recognize the name of the disease from photos in specialized Internet articles on gardening sites.

Blackleg

Seedlings are primarily threatened by the common “black leg”, which appears in stuffy, humid and poorly lit environments. The infection can be caused by rot bacteria or molds and is transmitted through soil and untreated seeds.

Infected seedlings do not survive; they sag and then die. The pathogen attacks the roots and stem at the base, cutting off the access of water and nutrients to the top.

Fighting the infection is practically useless. It is better to take preventive measures: disinfect the soil, tools, boxes, ventilate and darken the room.

Bacteriosis

Seedlings become ill with this disease through undisinfected seeds or with the help of insects. Seedlings develop poorly, small leaves turn pale and may curl outward. The flowers lose their bright yellow color, becoming whitish. The fruits stop forming. Tomatoes are uprooted and destroyed, and the soil is disinfected.

Fusarium wilt

A fungal disease spreads through soil microflora. It crawls along the seedling from bottom to top, first the edges of the lower leaves turn yellow, then the higher ones. Plants cannot be treated; they are destroyed, and the soil in the greenhouse is spilled with a solution of potassium permanganate.

Bacterial canker of tomato

A very dangerous disease that a vegetable can become infected with at any period of development. Most often, the infection appears already at the stage of 1-3 true leaves. The bacterium is transmitted through soil, seeds, and tools. Small whitish spots appear on the plants, then turn yellow around the edges and curl. Due to damage to the vascular system, the tomato wilts.

It is impossible to fight cancer; seedlings are immediately removed. You can prevent its occurrence by warming the seeds before planting.

Thin leaf virus

Sometimes found in hot spring under strong light. The infection is imported into the country with Dutch seeds that have not been treated with antiviral agents. It cannot be treated, and the infected plant does not bear fruit.

Yellow curl of tomato leaves

Carried by whiteflies. In appearance, this viral disease can easily be confused with chlorosis, deficiency of phosphorus, iron, magnesium, and yellowness of the apex. If infected early, the plant grows poorly and does not set fruit. A diseased tomato bushes heavily, the leaves curl and turn yellow. The tomato must be destroyed immediately.

It is not always possible to answer the question: why seedlings are affected by a fungal pathogen. After all, the infection could have entered the plantings with the wind, soil, insects, and seeds.

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.