Why do tomato leaves turn yellow in a greenhouse and in open ground

Why do yellow spots form on tomato leaves? Does it matter on which leaves - upper or lower - they are formed? How to process tomatoes if the leaves began to turn yellow?

Why do the leaves of tomatoes turn yellow in a greenhouse and greenhouse

If you notice that the lower leaves of your tomatoes have begun to turn yellow and wither, the reason lies in one of the following problems.

1. You do not follow the watering regime. Both excessive and insufficient moisture are equally dangerous for tomatoes. When the soil is dry, water the tomatoes sparingly. When the optimal mode of irrigation of the beds is restored and the soil is regularly loosened, the plants will quickly come to their senses.
2. Tomatoes get sick. Tomato leaves turn yellow when affected by Fusarium wilt or other diseases. To save the crop, you need to recognize the disease in time and start fighting it.
3. The plant lacks trace elements and minerals. Perhaps your tomatoes just need to be fed. During the fruit ripening period, plants need complex nitrogen fertilizers.
4. The root system of tomatoes is damaged. The problem can be hidden both in the fact that the roots of plants are eaten by pests, and in the fact that you accidentally damaged the roots when transplanting seedlings into the ground or loosening. If it is a matter of mechanical damage, the yellowing of the leaves is due to the fact that the plant throws all its strength into the formation of new adventitious roots. As soon as the root system recovers, the leaves will return to a healthy green color.
5. Too high humidity in the greenhouse. The optimal humidity level in a greenhouse or greenhouse for tomatoes is 60-70%. If the air is too humid, the leaves may begin to turn yellow and rot. Especially if the temperature in the greenhouse has dropped below the recommended one.

What causes the leaves of tomatoes in the open field to turn yellow

Basically, yellow spots on the leaves of an outdoor tomato appear for the same reasons as when grown under cover. However, there are some nuances.

1. Low air temperature. This problem is practically unknown to greenhouse tomatoes, but "street" tomatoes during a cold snap can get hypothermia, the result of which is yellowing of the leaves.
2. Damage by diseases and pests. Fusarium, as well as other diseases of tomatoes, can lead to yellowing of the leaves of the plant. In addition, this problem may indicate that the roots of the plant are affected by pests.
3. Lack of watering. If the weather turned out to be hot, dry, and the tomatoes did not receive the necessary amount of moisture, their leaves begin to turn yellow.
4. Excess moisture. Excessive watering is also dangerous and threatens with the appearance of yellow spots on the leaves of the tomato.
5. Deficiency of elements and minerals in the soil. Nutrient deficiencies, especially nitrogen and potassium, can also cause yellowing. To return the green color to the leaves of tomatoes, it is necessary to feed them with complex fertilizer.
6. Root damage. If you break the roots of tomato seedlings when planting or damage them when weeding or loosening, the leaves may turn yellow for a short time. As soon as new roots form on the plant, the green color will return.

Why do the leaves of tomato seedlings turn yellow and dry

Yellowing of the leaves of tomato seedlings is most often associated with care errors or improper growing conditions.

1. Small container. Cramped conditions do not allow the root system of seedlings to develop normally. And this means that the leaves will certainly turn yellow and fade.
2. Overwatering or underwatering. So that the seedlings do not dry out and do not rot, water them moderately.
3. Hypothermia. Maintain the optimal temperature for the development of tomato seedlings - 18-22 ° C.
4. Lack of nitrogen. For good growth, seedlings need a sufficient amount of nitrogen in the soil. If you follow all the recommended growing conditions, and the leaves turn yellow anyway, the plants may need a nitrogen supplement.
5. Lack of lighting. Without good sunlight, photosynthesis is impossible. It is not surprising that tomato seedlings begin to turn yellow in dark rooms.
6. Soil acidity. Any problem is easier to prevent than fix. Therefore, it is advisable to initially use specially prepared soil for growing seedlings. If it turned out that the soil in the containers with seedlings is sour, the situation can be corrected by adding a little ash.

Why do tomato leaves turn yellow after planting

1. Wrong watering. If you water tomato seedlings too hard, or, conversely, irregularly, this can lead to yellow spots on the tomato leaves.
2. Damage to the root system. If the root system of tomatoes does not function well, this will inevitably lead to yellowing of the leaves. The reason may lie in mechanical damage to the roots when planting seedlings, weeding or loosening. In this case, the plant will recover on its own.
3. Diseases and pests. When the plant is damaged by viruses and diseases, as well as pests, the leaves often begin to turn yellow. In this case, it is necessary to immediately save the plant and begin the fight against ailments and insects.
4. Hypothermia. If, after planting the seedlings in the ground, the temperature drops, the seedlings will begin to wither and turn yellow. You can save the situation by prudently covering tomatoes in adverse weather.

What to do if the top leaves of a tomato turn yellow

If only the upper leaves of tomatoes turn yellow, while the lower leaves remain green, the reason is the lack of nutrients.

1. Calcium. With calcium deficiency, the upper leaves turn yellow, the tips of the leaves are deformed, the flowers fall off, dark growing spots form on the top of the fruits. If you limed the soil before planting, most likely you overdid it with nitrogen fertilizers, which prevent the free absorption of calcium. You can correct the situation by spraying the bushes with calcium nitrate (20 g per bucket of water).
2. Sulfur. Sulfur "starvation" can lead to lignification and thinning of the stems, reddening of the veins and gradual yellowing of the leaves. In this case, the tomatoes are sprayed with a solution of magnesium sulfate (10 g per 10 liters of water).
3. Iron. A symptom of insufficient iron content in the soil is yellow spots in the center of the tomato leaf and along the midrib. To return the plants to a healthy color, they are sprayed with a 1% solution of ferrous sulfate or iron chelate. You can also carry out root dressing with the same substances. The yellowness should go away in a day.
4. Manganese. Signs of manganese deficiency are similar to those of iron deficiency. The only difference is that the color of the veins is heterogeneous, yellow-green. To restore the required amount of manganese, foliar treatment is carried out with a 1% solution of potassium permanganate.
5. Bor. Initially, with a lack of boron, the upper leaves retain a green color, but are deformed at the base. If the problem is not solved, the leaves turn yellow, the veins become dark brown. To prevent this, tomatoes are sprayed with a solution of boric acid (10 g per 10 liters of water).

What to do if the lower leaves of a tomato turn yellow

Yellowing of the lower leaves is less dangerous than yellowing of the upper ones, as it does not always indicate a disease of the plant. Most often, the plant gets rid of older leaves in order to direct all its resources to the development of fruits.

To make tomatoes feel good, you must follow the recommendation that we gave above:

• Water plants regularly but moderately.
• Avoid hypothermia.
• Timely carry out complex top dressing.
• Fight diseases and pests.
• Replenish missing elements. For example, yellowing of the first two pairs of true leaves, which is accompanied by their twisting upwards, may indicate a lack of molybdenum. In this case, yellowness first appears in the form of small spots, and then covers the entire surface of the sheet. The leaf veins remain green. In this case, it is necessary to treat the tomatoes with a solution of ammonium molybdate (2 g per 10 liters of water).

The yellowed lower leaves will sooner or later wither and fall off on their own, but it is better to remove them yourself so that the plants do not waste nutrients on them.

What to do if the edges of the tomato leaves turn yellow

Tomato leaves turning yellow at the edges indicate insufficient nutrition of the plant with essential elements.

1. Nitrogen. The leaves turn yellow and burn at the edges, later they die. Plants stretch, become weak, stunted. In this case, it is necessary to carry out nitrogen fertilizing. For example, urea (1 tablespoon per 10 liters of water).
2. Potassium. Young leaves are deformed, twisting with a tube, old ones turn yellow at the edges. It is necessary to treat the tomatoes with potassium nitrate (1 tablespoon per 10 liters of water).

What to do if the leaves of tomatoes wither and turn yellow

Withered and yellowed tomato leaves are most often the result of hypothermia or insufficient watering of plants.

1. "Warm" the tomatoes. To do this, put them in a warm place and pour water at room temperature.
2. Feed the tomatoes. Wilting and yellowing of the leaves may be due to a deficiency of the necessary elements. You can use complex nitrogen fertilizers.
3. Remove seedlings from bright sun. Direct sunlight is also better to oppress tomatoes. Ideal lighting is diffused light.

What to do if the tomato leaves turn yellow and curl

Curling of tomato leaves is an "aggravating circumstance" that indicates more serious problems than simple hypothermia. There are three reasons for yellowing and curling leaves.

1. Lack of minerals and elements. With a shortage of substances necessary for the growth of tomatoes, it is necessary to feed the plants. How to process tomatoes? The easiest way is to apply a ready-made complex fertilizer. In addition, you can sprinkle the bushes with wood ash with a layer of 0.3 cm, or pour 0.5 liters of potassium nitrate solution under each bush (2 tablespoons per bucket of water).
2. Uneven leaf growth. With a sharp jump in growth, tomato leaves can curl. This is because the leaf is stretched along, and the leaf plate itself does not have time to grow after the midrib. This problem can be solved by placing the tomatoes in a sunny place.
3. Pest damage. Twisting of the leaves may indicate that the plant was attacked by tick larvae or aphids. To get rid of pests, you can treat tomatoes with folk remedies. For example, every five days, spray them with an infusion of onion peel (1 tablespoon per bucket of water, leave for a day). You can also spray tomatoes with a 1% solution of potassium permanganate.

tomato, seedling, disease