Cucumbers are one of the most common vegetable crops. These vegetables are quite unpretentious, grow well and bear fruit in a nutritious soil, but often their leaves begin to turn yellow before the end of the summer season. There can be many reasons why the leaves of cucumbers turn yellow, but they are all divided into 3 groups: violation of agricultural technology, the presence of diseases, or a lack of fertilizers.

This article will talk about why cucumbers turn yellow, why cucumber seedlings turn yellow in a greenhouse and what to do, how to deal with yellowing on cucumber leaves.

Optimal conditions for growing cucumbers

First of all, plants need to create the necessary conditions for growth and development, otherwise the vegetables may show signs of disruption of care or beginning diseases.

Open field cucumbers

In the open field

After planting seeds in open ground (or when planting seedlings in beds), you need to provide them with some care.

Important! The main thing is to observe the watering regime. If these plants do not have enough moisture, they will begin to dry out. If the soil moisture is too high, the roots of cucumbers may begin to rot or fungal diseases will begin. It is also necessary to make the necessary fertilizing on time, otherwise the plants may show signs of a lack of some macro- and microelements.

In greenhouses

Greenhouse plants can suffer from excessive humidity at high temperatures. In such conditions, plants are most often affected by fungal diseases, which will be difficult to get rid of.

Cucumbers in the greenhouse

It is necessary to ensure that watering is regular, but not excessive. Otherwise, excess moisture will settle on the walls of the greenhouse (especially if the air temperature is high).

Note! It is in such conditions that fungal spores usually develop, which will cause the development of fungal diseases.

To avoid the development of fungal diseases or decay of the root system of cucumbers, you need to water the cucumbers in the first half of the day so that moisture can be absorbed into the soil during the day, as well as air the greenhouse during the day.

Houses on the balcony

When growing cucumbers at home on the balcony, you must also observe the temperature regime, a certain humidity in the room. In addition, at home, cucumbers grow in small containers, so nutrients from the soil are quickly drawn out by plants. In such conditions, vegetables need to be fed more often than in greenhouses or in the beds in the garden.

Growing cucumbers at home on the balcony

Balcony plants need sunlight, but not direct sunlight, which can burn cucumber leaves and stems. Ideally, if the balcony where the cucumbers grow faces the south-east or south-west sides. If the balcony faces south, at lunchtime you need to shade the plants from the hot sun.

Important! With the correct application of moisture, the soil should be moderately moist at a depth of 8-9 cm.

Why do the edges of the leaves turn yellow in cucumbers, what to do

Why do cucumber ovaries turn yellow

Important! It is worth taking action immediately if the appearing yellowness is not associated with the natural process of wilting of the tops.

The main reasons for the appearance of yellowness on the foliage of cucumbers:

  • Violation of the mode of moisture introduction. With too rare watering or with frequent, but in a small amount, the plant begins to show signs of a lack of moisture.The first symptom is the appearance of yellow spots or borders on the leaf. But excessive application of moisture is also detrimental to cucumbers - they begin to rot.
  • Lack of nutrients. Perhaps, before planting, a small amount of nitrogen fertilizers was applied to the ground, and with a lack of nitrogen during the period of active growth of the vegetative mass, yellow spots may appear on the leaves. This happens especially often if the cucumbers lack nitrogen and calcium.
  • Air temperature too low. In this case, vegetables can be stressed, as a result of which the foliage begins to turn yellow.
  • Sunburns. Watering vegetable crops in the beds in the daytime, you can accidentally hit the foliage with a stream of water. In this case, the appearance of yellow spots on the leaves indicates a sunburn. Therefore, it is better to water the cucumber beds in the morning or evening.
  • Diseases and viral infections. The first sign of an incipient disease is yellowing and wilting of foliage. Fusarium is one of the main diseases that begins with yellowing of the vegetative mass of cucumbers.
  • Root damage. They can be eaten up by pest larvae. Also, the roots could be damaged during transplantation to a permanent place, when loosening row spacings or when removing weeds.

Yellowness on the foliage of cucumbers

If the foliage not only turns yellow, but its edges and tips begin to curl, this indicates big problems:

  • lack of macro- and microelements. When vegetable growers notice that the color of the leaves becomes pale, the leaf plate turns downward - this may be a sign of a lack of nitrogen. It is necessary to carefully examine the vegetative mass - if the leaves are stretched along, and the leaf plates do not grow, the cucumbers should be fed with nitrogen fertilizer and the plant will recover;
  • powdery mildew. This disease usually affects plants in July. It appears on foliage, which begins to turn yellow and curl. To prevent infection, greenhouses and greenhouses should be regularly ventilated, and the plants should be treated with Bordeaux liquid;
  • pest attack. Sometimes curling of foliage, lightening and yellowness are the main signs of an attack on cucumbers by "harmful" bugs. In this case, you need to inspect the back of the leaves, if aphids or spider mites are found on it, you should treat with insecticidal preparations;
  • viral infections. If all the necessary measures have been taken, fertilizers have been applied, pest control has been carried out, and the plants do not return to normal, the cucumbers, most likely, have become infected with some kind of viral infection. There are no methods of combating such diseases, so the affected plants are simply destroyed, and the soil is disinfected;
  • low fever or sunburn. Yellowing of leaves can begin in case of non-observance of the temperature regime in greenhouses. When the foliage of seedlings or adult cucumbers comes into contact with glass that is hot from the sun or too cold in greenhouses, yellow spots appear on the leaf plates. It is better to plant the plants so that they do not touch the walls of the greenhouse;
  • if the humidity in the greenhouse is too low, foliage begins to curl up in order to reduce the evaporation area. In this case, you need to increase the number of waterings and increase the humidity in the greenhouse.

The foliage of cucumbers can not only turn yellow, but also curl

Having found out the reason, it is worth figuring out what to do if yellow spots appear on the leaves of cucumbers.

How to fix the situation

Why do cucumber seedlings curl leaves

If cucumbers are already damaged by pests or pathogenic microorganisms, folk, biological or chemical agents can be used to treat them.

Traditional methods of treating foliage that is starting to dry are most often effective at the initial stage of the disease. The following products and solutions are popular:

  • spraying the yellow vegetative mass with a solution of milk or kefir whey. For 5 liters of water, you need to take a liter of whey, add an incomplete glass of sugar and mix.This spraying also promotes better ovary formation;
  • if pests have appeared on the foliage of cucumbers, they can be destroyed with an onion solution. It is prepared as follows: 700 g of onion husks are placed in a bucket of water and brought to a boil. Then this broth is infused for 10-12 hours, filtered. The broth is diluted with water in a ratio of 1: 4, the diseased plants and soil are sprayed;
  • at an early stage of the disease, the treatment of plants and soil with a weak solution of magnesium permanganate is effective;
  • To scare off the whitefly from the beds with cucumbers will help tobacco, which is planted in the aisles;
  • against aphids, you need to use an ash-soap solution (a glass of ash and ½ a piece of laundry soap are diluted in a bucket of water);
  • you can remove pests from the leaves with a soft sponge and soapy water, or you can pick the insects by hand. But these methods are effective only with a small number of pests;
  • to prolong the fruiting of these vegetables, you can feed them "on the sheet" with a solution of urea.

Aphids on cucumbers

If folk remedies do not help, biological drugs will come to the rescue. The following biological preparations are most effective for processing seedlings and adult plants:

  • trichodermin,
  • planriz,
  • pentaphage C,
  • Fitosporin M,
  • gamair,
  • alirin B.

Chemical preparations for the treatment of cucumbers are used as a last resort, because such agents are very toxic, negatively affect the soil microflora and can accumulate in fruits, negatively affecting the human body.

For processing cucumbers, you can use "Trichodermin"

Actellic can be used against pests, which destroys almost all known insects and their larvae. This drug quickly penetrates foliage and kills insects. This remedy is most effective at air temperatures above 16-17⸰С.

Note! In greenhouse conditions, the action of Aktellik lasts for 12-14 days, in the open field - 8-10 days.

Another broad spectrum insecticide is Fufanon. After treatment, the effect of the drug lasts up to 3 weeks. This drug is very toxic, therefore, when working with it, you must use personal protective equipment and do not work with it for more than 120 minutes. Insects die in 1.5-2 hours.

The insecticide of the new generation is Confidor; very little of this preparation is required for processing. Pests do not get used to the drug, so you can use it to process cucumbers several times per season (if necessary). The action of the drug lasts up to 30-35 days. Pests die within 3 hours after contact with this agent. Conifor is not washed off during watering and rains, it works even in hot weather.

Prevention

Why do cucumbers have leaves curling inward?

We should not forget about preventive measures to prevent diseases of vegetable crops. It is always easier to prevent an infection or pest attack than to fight it. You must adhere to the following rules:

  • compulsory observance of crop rotation. Cucumbers should not be grown in the same place every season, nor should they be planted after zucchini or pumpkins - this can lead to the occurrence of the same diseases;
  • these vegetables should be watered regularly and generously. After watering, it is better to mulch the beds with hay or cut grass. In this case, moisture will evaporate less, and a layer of mulch will protect the soil from overheating or cooling;
  • after the sprouts appear, they should be periodically sprayed with a solution of soap with iodine (100 g of soap, a few drops of iodine and a liter of milk are needed per bucket of water);
  • cucumbers can be fed with a solution of "green tea" - a large tank is 2/3 filled with grass, top up with water and insisted for a week. Then 0.5 liters of this infusion is diluted in a bucket of water and the plants are watered. Under each bush of cucumbers, you can pour half a glass of wood ash;
  • so that the foliage does not have time to turn yellow, you can use a folk remedy: a loaf of bread is soaked in a bucket of water for 8-10 hours.Then a bottle of iodine is added to the resulting mixture, mixed. 2 liters of the mixture is diluted in 20 liters of water and sprayed on the plants. This treatment is carried out every 14 days;
  • at the beginning of summer, cucumbers are sprayed with a solution of soda (for 10 liters of water, you need to take 30 g of soda). This spraying helps fight fungi that die in an alkaline environment.

When carrying out all preventive measures, as well as observing the rules for leaving the foliage of cucumbers, it is unlikely that it will begin to turn yellow. It is only necessary to comply with the irrigation regime, apply top dressing on time, carry out preventive spraying of the soil and plants from possible diseases and pests.