Every gardener, when planting vegetables, hopes for a bountiful harvest. Growing seedlings and careful care of beds - necessary work for those who cultivate their own plants. Sudden yellowing of foliage is cause for concern. After all, this leads to a decrease in yield and even the loss of a favorite crop. What to do if tomato leaves turn yellow? Possible causes should be analyzed and unfavorable factors eliminated.

Physiological reasons for oppression of seedlings

Insufficient soil volume

Stress

Injury to the root system

Improper irrigation

Excess humidity

Lighting and heating

Thickness

Burns

Violation of agricultural cultivation technology

Soil

Nutrition

Warm

Mechanical injuries

Diseases and pests

Conclusion

Physiological reasons for oppression of seedlings

Strong plants come from good seedlings. Therefore, you need to care for indoor seedlings with attention and care. Pick up when a true leaf appears, not a cotyledon, and transplant into the greenhouse at the right time.

Why do the leaves of young or adult tomato plants turn yellow? There are several reasons for this condition:

• lack of land, watering, nutrition, lighting and heat;
• transplant stress;
• root damage;
• high humidity indoors;
• thickening;
• sunburn.

Insufficient soil volume

Sometimes seedlings growing in small cups on a windowsill in a house do not have enough land to develop. An overgrown plant fills the soil completely with its roots and begins to wither from lack of nutrition.

Fertilizing will not help here. Therefore, it is worth paying close attention to when seedlings should be planted either in larger containers or in the vegetable garden.

Overgrown plants with wilted or yellow foliage do not take root well in a new location and are delayed in development. When watering, root formation stimulants and foliar fertilizer are added to the water.

Stress

When transplanting seedlings to open ground sometimes its lower cotyledon leaves turn yellow. This occurs due to unfavorable conditions: insufficient watering or lighting, strong sun, low temperature. Changing location for a plant with an open root system is always stressful. These same factors are the reason why the leaves of seedlings in a greenhouse turn yellow.

To prevent leaves from falling on the plant, you need to water it well with the addition of rooting agents and shade it in the first days of growth.

Injury to the root system

Damage to the roots of seedlings during planting or replanting, if they are not growing in individual cups, is a common occurrence. Trimming the root tip of a tomato when planting in the ground is even recommended to increase the bushiness of the fibrous part of the root system.

However, after such a procedure, the seedling suffers. Therefore, when picking or planting, it is worth feeding young plants and treating them with anti-stress drugs Tomaton, NV-101 or Kornevin.

Improper irrigation

If they turn yellow lower leaves tomato seedlings due to lack of water, then the gardener just needs to water the plantings and carefully monitor the plants. Tomato wilting due to lack of moisture is difficult to confuse with something else. At the same time, the leaves and stems not only turn yellow, but also wither. They recover quickly after the necessary procedure.

It is more difficult to restore a tomato when the soil is very waterlogged, as rot of the leaves and stems often begins. The seedlings die due to an infection called “blackleg”. Watering is stopped until the soil dries, and the plantings are treated with a fungicide against infections.

Excess humidity

Damage to tomatoes is caused by high humidity in a greenhouse structure. Values ​​above 60-70% lead to yellowing and rotting, especially at low temperatures. Poor ventilation not only depresses plants, it helps the development of many fungal infections. Therefore, it is necessary to ventilate greenhouses and greenhouses regularly after watering.

Lighting and heating

When growing indoor seedlings fertilizers are applied to the soil before planting. Then the plants are fed twice before planting in the beds.

There is enough natural light in March. But on a north window it may not be enough. In case of depressed state of plants, pallor and yellowing of the lower cotyledon leaves, artificial additional illumination is organized.

Seedlings growing indoors are protected from the cold. In spring there are frequent frosts with a sharp decrease in temperature, especially at night. Due to cold weather, the seedlings' metabolism becomes difficult, development is inhibited, the leaves curl, and then turn yellow and fall off.

It is impossible to save frozen seedlings. Therefore, you need to monitor the weather forecast and bring boxes with seedlings into the house if there is a threat of night frost.

Thickness

Seeds planted in one box and growing without picking often grow weak and thin, lacking sunlight. The situation cannot be corrected by fertilizing or watering. It is worth planting fewer plants in individual cups, then the created conditions will contribute to better development of tomatoes.

Burns

Strong spring sun often causes leaves on seedlings to burn. Where the lighting was particularly strong and damaged the tissue, a yellow or brown spot appears. It does not grow, as with an infection, but it does not disappear. In this case, the plantings must be shaded.

Violation of agricultural cultivation technology

Just like the condition of young seedlings, numerous natural factors affect an adult tomato bush. And only conditions suitable for development have a beneficial effect on the growth of tomatoes. Deviations from standard indicators lead to developmental inhibition.

Soil

Tomatoes prefer loose neutral sandy loam or light loam. Acidic soils are neutralized with lime, chalk, and ash. Peat is added to limestone.

Sometimes clay soil is very wet in any weather; plants suffer from acidification, excess water and lack of oxygen in the soil. It is difficult to grow in such conditions; tomatoes turn yellow and wither. The area is drained and sand or peat is added to increase looseness.

Nutrition

It is not easy to correctly determine the lack or excess of nutrients in the soil, which is why growing tomatoes becomes problematic and the leaves on the plants turn yellow:

• lack of nitrogen is expressed in the fact that not only the tomato leaf becomes yellow and small, but the whole plant looks weak and lifeless;
• a lack of potassium leads to stiffening of the shoots, the appearance of spots and dark stripes on the fruits, the lower leaves turn yellow and dry out along the edges, and new ones that grow begin to curl;
• Magnesium deficiency is easily determined by yellowing of the leaf between the green veins, since the formation of chlorophyll is disrupted;
• The poverty of the soil in microelements leads to the fact that the top young leaf on vegetable bushes turns yellow. This reaction is noticeable with a lack of calcium, boron, sulfur, iron, and manganese.

Signs of illness and micronutrient deficiencies vary greatly. If a suspicious leaf color is detected, you need to observe the tomatoes for 1-2 days, find similar examples on videos on the Internet and determine the cause.

In addition, with a lack of certain microelements, one bush in a row may turn yellow; this depends on the variety and location of the plant.

What can improve the situation? Foliar feeding of tomatoes with a solution of complex fertilizers: Kemira Lux, Mortar, Universal, infusion of comfrey leaves.

Warm

Intense heat often leads to the fact that tomato plantings suffer not only from a lack of water, but also from increased temperature. In this case, the lower leaves turn yellow and fall off first. Moist soil and spraying tomatoes in the morning or evening will help alleviate the condition of the plants.

Autumn yellowing of leaves after air temperature drops to critical value leads to irreversible death of tomatoes. This process begins at the end of September. The season is ending and it’s time to start harvesting and cleaning the garden.

Mechanical injuries

Damage to the roots during weeding or hilling can sometimes cause yellow leaves. Mature plant It’s unlikely that it can be damaged that much, but something young can be damaged quite well.

When loosening the soil, no one will cut the main root. But small suction roots are often damaged. At the same time, the whole plant looks strong, and only the lower leaves begin to turn yellow.

It is worth watering the plant well, adding an anti-stress drug to the water and hilling the stem with damp soil. The additional roots that have grown will increase the feeding area, and the yellowing of the leaves will stop.

A good way to avoid such trouble is to use mulch, which keeps the soil loose and moist.

Diseases and pests

Tomato leaves can turn yellow due to some fungal infections and damage by insect pests.

Diseases caused by various pathogens most often appear on tomatoes in the form of spots on the leaves:

• late blight;
• fusarium;
• mosaic.

You can determine a specific disease from a photo on the Internet or reference literature. The leaves begin to quickly dry out and fall off, and the plant dies if treatment is not started.

In this case, fungicides such as HOM, Fitosporin, Mikosan, Bordeaux mixture that destroy pathogens.

The pest that causes tomato leaves to turn yellow is the mole cricket. This is a large underground predator that feeds on plant roots, manure, humus, earthworms and insects.

The roots of tomatoes can be damaged by underground inhabitants: wireworms, larvae chafer, root-knot nematode. This invariably leads to yellowing of the lower leaves and gradual drying of the entire plant. These pests can appear on the site due to unrotted manure, high humidity, abundance of weeds.

Conclusion

What to do if tomato seedlings or leaves on an adult plant suddenly turn yellow? First, you should establish the cause of this condition, and then do what will help get rid of it. But best way– prevent the problem by growing hardy and strong seedlings, and then a strong and healthy tomato plant.

7 rules, following which you can get excellent seedlings and big harvest tomatoes.

Any plant cannot live without heat, sun, water and soil. Tomatoes are no exception; for normal growth they need:

• Quality seeds
• Fertile soil
• Sufficient light
• Moderate watering
• Optimal temperature earth and air
• Protection from diseases and pests
• Top dressing mineral fertilizers

If you have completed everything necessary conditions, then the plants will delight you with their powerful appearance and rich harvest. If you made a mistake on at least one of the points, they will upset you with frail shoots and a meager harvest, if any at all.

What to do if the tomato seedlings have become very elongated, thin and long?

After the shoots have appeared and pleased their owners, the real important stage in plant development. At this stage, plants must receive temperatures of the ground and air that are acceptable for growth, as well as sufficient light and moisture. What happens if optimal conditions are violated?

If the soil in the seedling pots is too cold, and the air temperature is either too low or too high, the plants will not be able to fully develop.

They will also not be able to develop normally if they receive too little light. If the seedlings are stretched out due to lack of light, you can save them by giving them enough light.

Why are tomato seedlings purple and growing poorly?

Why in a relatively warm house, if you grow seedlings on the windowsills, does the ground remain cold? Because often and thickly, the cold that comes from the windows excessively cools the pots with seedlings. To experiment, place a room thermometer on the windowsill or on the soil of your greenhouse if you are growing seedlings under film, and measure the temperature. The optimal soil temperature is from 16 to 18 degrees. If the ground is cold, the plants will not grow well and the color of the seedlings may turn purple.

Why do the leaves of tomato seedlings turn yellow: what to do?

The air temperature for seedlings should be from 25 to 28 degrees. Plants will be stunted if temperatures are above or below these levels. Separately, I would like to say about the illumination of plants.

If there is catastrophically little light, the seedlings can stretch out in just a few days. It will have a yellow color and thin elongated stems. You can expect a good harvest from such seedlings only if you can give the plants enough light.

Why do tomato seedlings wither and fall?

Unfortunately, on the windowsill without additional lighting, even if the windows overlook sunny side, the plants will not be able to receive enough light. The only way out in this situation is to use artificial lighting. These can be special lamps that are used in industrial greenhouses and which are expensive or inexpensive fluorescent lamps.

The same failure may await those gardeners who sowed seeds in greenhouses with film cover. Because early spring There is not enough sunlight, which can be lost when passing through a dense film.

Mold on the ground in tomato seedlings: what to do?

When watering seedlings, it is better not to add water than to give it in excess. It happens that gardeners are so keen on caring for their plants that they begin to water them every day or even several times a day. They water it because they noticed the top layer of soil in the pots drying out, while inside there is an excess of moisture.

Black leg in tomato seedlings: control measures

Excessive watering leads to suppression of plants, creates favorable conditions for the development of fungal diseases of the root system and ultimately the death of seedlings. How to determine that plants need watering?

The easiest way to deal with this situation is to not water the plants until you notice some wilting due to lack of moisture. In this case, the leaves are less elastic and slightly drooping. Plants need to be watered warm water. If you use chlorinated tap water, remove the chlorine from the water.

To do this, just collect water in a bucket and let it stand for 2-3 days. Chlorine is a gas and is lighter than water, so it will completely leave the liquid during this time.

Feed the seedlings with mineral fertilizers. This should be done no more than once a week complex fertilizers. You need to be careful when using fertilizers like saltpeter. Due to the high nitrogen content in the soil, plants can become very elongated.

Treatment of tomato seedlings against diseases

Avoid infecting seedlings with pests and diseases. Since disease infection in a greenhouse or when growing seedlings on windowsills occurs mainly due to contaminated soil, use only healthy soil for this purpose. If you take it from your garden, then take it from beds where tomatoes and related crops, say potatoes, did not grow.

Phytophthora on tomato seedlings: combating it

Late blight is considered a disease of open ground and rainy and cool weather is favorable for its development. For plants to become ill with late blight, they must be exposed to unfavorable weather conditions for 3-7 days.

If the tomato seedlings are under cover or in the house, the likelihood that they will get late blight is very low. To prevent the disease, you need to prevent water from getting on the leaves of plants and water only the ground. If brown spots still appear on the leaves - treat them with fungicides against late blight.

White spots on the leaves of tomato seedlings: what to do?

White spots on the leaves of seedlings may be the result of burns from the sun or lamps used to illuminate the plants. So, if you’re not used to sunlight transfer the seedlings to the beds or expose the pots to the sun; the plants will not be able to cope with the resulting load and will get burned.

Preventive measures against burns can include gradual adaptation of plants to the new light regime. If burns have already occurred, the affected leaves can be torn off. The plant will gradually return to normal and produce new leaves.

The leaves of tomato seedlings curl, wither and dry out: what to do?

If the leaves of seedlings curl, this can be either the result of disease or the result of plant oppression by pests. What to do if the plants are sick and you can’t tell by their appearance what’s happening to them?

The only way out in such a situation is to try to correct errors with temperature conditions, lighting the plants, watering them and treating them with fungicides against diseases and pest repellents.

Whitefly - white midges on tomato seedlings: how to fight?

Maybe someone will be surprised that plants located on a windowsill or under a film cover can have pests.

Unfortunately, they exist if land infected with these pests was used. In particular, the whitefly and its larvae can cause enormous damage to tomatoes, which in a matter of days can turn green plant in the stunted and feeble. They will help to cope with the problem of spraying leaves with products against this pest.

Aphids on tomato seedlings: how to fight?

Aphids may appear on tomato seedlings if soil contaminated with this pest was used. You can fight aphids by spraying the plants chemicals from aphids. Such as tanrek, confidor, spark bio and others.

Unfortunately, it happens that all efforts to improve the health of the plant are in vain. This can happen if improper care of the plant, disease or pest oppression of the plant has been too long. The only way out of this situation may be to replant the seedlings.

How to choose tomato seeds?

Sow only proven, high-quality seeds. If you buy seeds in stores, use only proven ones. retail outlets. Because counterfeits in the seed market have reached catastrophic proportions due to the fact that it has simply become unprofitable to trade in high-quality seeds.

Quality seeds are half the success in growing tomatoes

If you collect seeds from your tomatoes, choose for this purpose only healthy and powerful bushes that have produced good harvest. Sometimes seed disinfection is required. Because they can be infected with pathogenic viruses. Disinfection, if done correctly, does not affect the quality of the seeds, but may reduce germination. Therefore, you will have to increase the number of seeds sown.

In what soil do tomatoes grow best?

Sow the seeds in soil ideal for this crop. The soil for seedlings should not be too light and not too heavy. It must be said right away that the soil taken from the garden bed will be heavy if your garden is located on black soil. And soil purchased in stores called “for seedlings” will be too light due to the high content of peat in such soil. Therefore, the ideal option would be: mix 50% of the soil from the garden bed and 50% of the soil for seedlings thoroughly and fill the seedling cups or trays with this soil.

You will need to think in advance that excess water after watering the plants will need to flow freely from the cups. This means that they must have a sufficient number of holes at the bottom to drain excess water.

All these wisdom are easy to remember and use when growing tomato seedlings. And most importantly, if you still fail in growing seedlings, do not give up, but roll up your sleeves and correct your mistakes, grow new beautiful, healthy and powerful seedlings.

VIDEO: How to grow healthy seedlings?

Kira Stoletova

Those who have at least once encountered growing tomatoes know firsthand how often the leaves of tomato seedlings turn yellow. It is worth saying that this problem can lead to loss of harvest, so you should not turn a blind eye to it. It happens that the disease develops at lightning speed, literally, in one evening; it also happens that the process is delayed and the tomato seedlings gradually turn yellow. Gardeners and gardeners are wondering why this is happening, what is causing such changes. Today we will describe in detail the reasons why tomato seedlings begin to turn yellow, how to save the bush and how to prevent yellowing of tomato seedlings.

Causes of yellowing tomato leaves

It is worth saying that growing tomatoes is a fairly simple and straightforward process, and the vegetable itself is considered one of the most unpretentious. If you notice any deviations from the norm in the development of the plant, you should immediately understand the reasons and make attempts to eliminate them, the same applies to yellowing of tomato leaves.

The fact is that when growing any crop, be it a vegetable or a fruit, there are its own requirements, the failure of which leads to the development of certain problems. Thus, if mistakes were made when growing tomatoes, a problem such as yellowing of the foliage of tomato seedlings may develop. We list the most common answers to the question why the leaves of tomato seedlings turn yellow:

• Too much watering
• A cramped container for tomato seedlings before the picking stage
• Lack of nitrogen in fertilizer
• It's too dark in the greenhouse
• Soil acidity levels are too high
• Pathology of the development of the root system or mechanical damage to the roots
• Sudden changes in temperature, most often hypothermia
• Violation of humidity regime (excess or lack)
• Poor or insufficient feeding
• Fungal infection

There are a lot of reasons for the yellowing of leaves of tomato seedlings, but most of them can be called one phrase - violation of the conditions of care and cultivation, since a lot depends on the person, namely on his actions aimed at growing bushes. Next we will talk about the most common reasons that cause yellowing of foliage.

Root system problems

In fact, any problems with seedlings almost always indicate that something is wrong with the roots. For example, when it comes to tomatoes, it often happens that their roots grow so much that they turn into one continuous lump that cannot be untangled. Of course, such metamorphoses cannot but affect appearance plants, that is, on the state of the leaves. The problem can be corrected by replanting so that the plant has more free space, but this does not guarantee that the leaves will regain their normal appearance, that is, they will stop turning yellow, and the bush will not die.

It also happens that root system gets too much space, which allows the bush to restart the growth system of new roots too often. As a result, it turns out that young roots grow all the time, which leads to yellowness on the foliage, after which they dry out, making room for new shoots. If the problem is not noticed in time and solved by replanting the bush, then there is a high probability that the tomatoes will die.

Temperature changes

Tomatoes are most afraid of sudden cold snaps, as they are a heat-loving plant. Moreover, this concerns not so much the upper part of the plant, but its root system, that is, the area that is located directly in the ground. The lower foliage on tomato seedlings may begin to turn yellow after the first incident, and often this does not go away without leaving a trace; there is a possibility that the bush will simply stop bearing fruit.

To make sure that the appearance of a yellow color on the lower leaves is just hypothermia, you should carefully examine the tomato leaf. When hypothermia occurs, bluish spots will appear on the greens along with yellow ones.

Damage to the root system

Often the cause of yellowing of tomato seedlings is simple mechanical damage to the roots. This can happen at any stage of plant care, for example, during planting seedlings, while you are loosening the soil, or during the period of getting rid of weeds.

Usually, such a problem should not be solved in any special way; everything resolves itself, that is, the tomatoes take root on their own. Usually, it takes about 2-5 days for the adventitious root shoots to develop, after which the cotyledon leaves will again acquire a green color.

Moisture deficiency

Despite the fact that tomatoes have a well-developed root system, the root can develop up to 2 meters in length, the plant does not tolerate a lack of watering. The fact is that the lower feeding part of the root lies not so deep, only at a depth of about 30 centimeters.

If you have organized insufficient watering, there is a possibility that the leaves will turn yellow. Often those leaves that are located at the top suffer; in addition, their shape changes, they curl inward towards the tips.

High humidity

If you water the plant too often, it also seems to affect the appearance of the bush. First of all, active leaf growth will occur, which will occur in the first half of the growing season. It is worth saying that with the active development of the vegetable, you can easily skip this moment, which will lead to the foliage turning yellow. If nitrogen stops penetrating into the soil, the leaves will become more lethargic and will certainly acquire a characteristic yellow-brown tint, and then completely fall off. Moreover, this will also affect the fruits; they may crack and lose their presentation.

Micronutrient deficiency in soil

Not only nitrogen deficiency negatively affects the condition of tomato foliage. Appearance yellow spots on the leaves can provoke a deficiency of many other microelements. For example, if a bush does not receive enough calcium, then chlorosis may appear, manifesting itself as blossom end rot on the tops. In addition, one of the characteristic features is the yellow color of the foliage.

If, in addition to a change in the color of the leaves, you notice some thickening of the leaves, as well as thickening of the stem, then we can say that the crop is not receiving enough sulfur. If, in addition to the leaves turning yellow on tomato seedlings, dry shoots are observed, even if the plant receives a sufficient amount of moisture, then we can say that there is not enough manganese in the soil.

Eat characteristic features that there is not enough iron in the ground if you notice that the foliage has turned yellow and the leaves have curled towards the top. If the leaves contain not only yellow, but also red color, then you should think about the fact that there is not enough magnesium in the fertilizing.

Fungus

turn yellow tomato seedlings maybe due to fungus. This reason It is caused not simply by an error in care, but is a separate disease that is classified as a fungal disease. It is worth noting that a characteristic indicator of damage by Fusarium fungus is not only yellowing of the leaves, but also a decrease in turgor. Externally, the bush will look as if the last watering was done about 10-14 days ago. The problem is aggravated by the fact that the fungus remains viable in the soil for quite a long time, which increases negative influence on the yield indicator.

The fungus begins its action from the roots, after which it rises higher, affecting the stems and then the leaves, changing their color from green to yellow. If the problem was discovered too late, there is a possibility that the vascular system of the tomato may lose its ability to absorb nutrients from the soil. This will entail irreversible changes, such as delays in development and growth, as well as loss of the ability to bear fruit. Even if the worst does not happen, and the bush bears fruit, they will not grow large, even if the desired variety of tomatoes was planted.

The source of infection can be an infected tomato seed, as well as the remains of composted vegetables, as well as the tools that were used to care for and harvest the crop. In addition, it is worth mentioning that wind and too high air temperatures can contribute to the spread of the fungus. Let's find out how to fight the disease to save the harvest.

Methods to combat fungus

Biological method

This type of fungal disease control is most often used in greenhouse conditions. You need to remove top layer soil, usually a depth of about 20 cm is selected. After this, fertilizer, most often manure, is brought into the greenhouse. After this, you can return the removed layer of soil to its place. If you believe scientific data, then complete disinfection will occur after 2 years. You are required to carefully care for the site, get rid of weeds in a timely manner and dig it up at least once a year.

Thermal method

In order to take advantage thermal methods, it is also worth removing the top layer of earth, choosing the same recommended depth, after which you need to store the earth in boxes. Next, you have to thoroughly disinfect the entire earth by heating it over a fire. It is worth saying that before this procedure it is important to generously moisten the soil. During the heating process, you need to constantly stir the soil so that it warms up evenly. Also make sure the temperature doesn't go above 100 degrees or it will kill everything minerals located in the ground.

Chemical method

Many people in the fight against fungus prefer more aggressive methods, for example, chemical ones, namely treating the soil with chlorine lime. Compared to the above methods, this one works much faster and more efficiently. In order to prepare the solution, you will need 200 grams of powder per 5 cubic meters. It is recommended to carry out chlorination in autumn period, this is the only way such treatment will not negatively affect the growth of the plant.

How to deal with yellowness on leaves

Many people wonder whether it is possible to save those plants that have yellow leaves. This can be done, but only initial stages when the problem has not become global. First, it’s worth reviewing the watering; perhaps mistakes were made. After they have been eliminated, you need to fertilize the soil, and the fertilizer mixture should contain the maximum concentration of salt. It is not recommended to exceed the concentration of the fertilizer mixture above 10 grams per liter of water, otherwise it may cause a burn. The prepared solution should be sprayed on the crop once a day until new foliage grows.

Why do the leaves of tomato seedlings turn yellow?

Preventive measures

In order to prevent the seedlings from turning yellow, you should take care in advance preventive measures, that is, you need to create the most acceptable conditions for growing tomatoes, then the leaves will not turn yellow. This includes all activities, from soil selection to compliance with humidity and light conditions.

As for fertilizing, it should be done exactly a week after the first shoots appear. Then it should be repeated after two weeks. In addition, it is important to harden the crop, that is, gradually accustom it to temperature changes. 2-3 weeks before planting, you need to strengthen the greens, namely, accustom them to the influence of the sun's rays, for example, on a windowsill. It’s good if conditions are created on the windowsill when the sun’s rays are not direct. To do this, the tray with seedlings is taken outside, starting from several hours, gradually increasing the time, after which they are brought home.

Do not forget to regularly water the beds with seedlings, but do not overdo it. It is important to choose the right container for its contents, it is important that it has a hole for drainage, that is, air access, and also to carry out picking in time, that is, planting it in a large container.

Now you know why the leaves of tomato seedlings turn yellow. In conclusion, let’s say that yellowing of leaves or their tips is not a separate disease, but just a signal that something is wrong with the plant.