What to do if cucumber leaves turn yellow

What to do if cucumber leaves turn yellow

Almost every summer resident and gardener at least once came across the fact that cucumber leaves begin to turn yellow, dry, wither, or some kind of spots appear on them. There are many reasons for this common problem. To save the cucumber crop, it is imperative to find out the specific reason and solve it so that this problem does not recur next year.

Why cucumber leaves turn yellow: 6 reasons

Insufficient lighting

If the lowest leaves inside dense cucumber thickets began to turn yellow, then the reason is only one thing - not enough light. The cucumber seedlings were planted very close to each other. Over time, the tops have grown so that sunlight cannot penetrate to each leaf, and even more so to the lowest ones. So they turn yellow.

Such yellowed leaves will not bring any harm to the cucumber culture. This also does not affect the harvest. Inspect the beds occasionally and remove any yellow or dry leaves.

Improper watering

Cucumbers are a moisture-loving culture. But an excess of moisture affects them as badly as drought. In temperate climates during the summer, cucumber bushes should be watered at least three times a week. In dry and hot weather, watering should be done daily.

The volume of water during irrigation should be such that the earth is soaked deeply, to the very cucumber roots. If they lack moisture, they will begin to look for it on the surface of the soil and dry out. This will lead to yellowing of the leaves and ovary.

Yellow leaves can also appear after prolonged rainy weather. Excessive moisture can cause rotting of the roots and stems and, as a result, yellowness appears on the leaves.

Fungal diseases

Yellowing of the leaves is caused by such common diseases as pityosis and fusarium. The fungal disease first leaves spots on the tops that resemble rust, then dry spots on the leaves. All the leaves dry out and fall very quickly, and the whole plant becomes lethargic and lifeless.

Most often, fungal diseases appear after sudden changes in temperature. For example, the daytime air temperature exceeded the thirty-degree mark, and the nighttime dropped to 12-15 degrees. Or the summer heat was suddenly replaced by a prolonged cold rain.


Spider mites and whiteflies love to feast on juice of cucumber leaves. After their appearance, all the leaves on the cucumbers turn yellow and dry out.

There is only one way to deal with this cause - by destroying pests. As a solution for spraying, both a folk remedy and a special chemical preparation are suitable.

Top dressing and fertilizers

Very rarely, the leaves on cucumbers turn yellow due to a lack of any nutrients. In such cases, feeding will come to the rescue. The main thing is to figure out which elements the plant lacks. This can be determined by the state of the leaves:

  • Magnesium and potassium are necessary if only the edges of the foliage dry out.
  • Manganese and iron - if dark green streaks remain on yellow leaves.
  • Copper - if only the upper leaves turn yellow.


Yellow leaves appear at the end of the cucumber season, when most of the harvest is harvested and the plant begins to age and coarse foliage.

What to do if cucumber leaves turn yellow: solution to the problem

A variety of preventive measures are considered the most effective treatment. So that problems do not appear on cucumber beds, it is necessary:

Observe the rules of crop rotation

Every year you need to choose a new bed for cucumbers. Since pumpkin and zucchini have the same fungal diseases, you should not plant cucumbers after these crops - the possibility of getting sick increases significantly.

Observe the rules of watering

Cucumbers are very fond of regular and generous watering. If it is not possible to water the beds in a timely manner, then mulching of the soil will come to the rescue, which will preserve moisture in the soil for a long time. Use any herb (even weeds) as mulch. The mulch layer will not only protect against drought, but also provide additional warmth and nutrients.

Use top dressing

Wood ash is an excellent prophylactic against pests and diseases, as well as a source of potassium. It is poured directly into the hole of the vegetable plant. And as a liquid organic fertilizer, it is better to use herbal infusion. Mineral dressings can also be used if desired.

Carry out preventive spraying and watering

Recipe 1. These water procedures must be started at the initial stage of plant development, when the first four leaves have appeared on the young seedlings. And then repeat it three times a month. For a large ten-liter bucket of water, add 1 liter of milk, 30 drops of iodine and 20 grams of regular laundry soap. Use for spraying.

Recipe 2. In a ten-liter bucket of water, leave a loaf of bread to soak overnight. After about 10-12 hours, the bread will be easily kneaded. Add a small bubble of iodine to this mixture. Spraying can be carried out 2 times a month throughout the summer season.

Recipe 3. To prevent the appearance of fungal diseases, use a soda solution for watering - add 1 tablespoon of soda to a large bucket of water. Watering with this solution is carried out at the beginning of summer.

Recipe 4. Universal solution that is suitable for watering and spraying:

With 10 liters of water, you need to pour about 100 grams of onion husks, boil and leave to infuse overnight under a closed lid. The strained broth must be diluted with water before use: 400 grams of water are added to 100 grams of solution. This solution will scare away harmful insects.

Recipe 5. Solution for better formation of the ovary and from yellowing leaves: mix 2 liters of kefir or whey with 10 liters of water and an incomplete glass of granulated sugar. Use for spraying.

Recipe 6. Pour the hay with warm water (in equal parts) and leave for 2 days to infuse. Use for spraying no more than 3 times a month. The infusion prolongs the fruiting period for the plant.

What you need to do to prevent cucumber leaves from turning yellow

After the emergence of shoots, when at least 3 leaves are formed on the sprouts, it is recommended to treat the cucumbers with the following composition: for one bucket of water, take 1 liter of milk, 30 drops of iodine and about 20 g of laundry soap. It is advisable to spray plants with such a composition every 10-12 days.

Dissolve 150 g of granulated sugar and 2 liters of whey in a bucket of water. The resulting solution must be watered and sprayed with cucumbers. This sposos is also suitable for peppers. Usually, soon after the procedure, new ovaries appear on the plants.

You can simply dilute milk whey in water by taking 1 liter of whey per 5 liters of water and spray the cucumbers with the solution.

It also happens that the leaves turn yellow due to an elementary lack of watering. Try adjusting the watering and the leaves may stop turning yellow.

Helps prevent yellowing of the leaves with a solution prepared on the basis of onion peels. Fill a 700 ml jar with onion husks, then pour the husks into a 10-liter container with water and put on fire. Bring the liquid to a boil, then remove from heat, cover the container with a lid and leave the broth for 12 hours. Dilute the cooled and strained liquid with water, taking 4 liters of water for 1 liter of solution. After that, you need to sprinkle the cucumber tops abundantly, and water the beds with the remaining liquid.

Soak a loaf of bread in water (you need to take about a bucket of water), and leave overnight. In the morning, knead the bread and pour the iodine bottle into the bucket. The resulting liquid must be diluted with water (take a bucket of water for 1 liter of solution) and sprinkle with cucumbers. This should be done at least once every 2 weeks. Store unused solution in a cool, dark place.

All of these methods will prevent the cucumber leaves from turning yellow and keep them green until fall.

The main causes of yellowing

The yellowing of the leaves in cucumbers is a condition called chlorosis. There are two types of chlorosis: infectious and non-infectious. You can distinguish the type of disease, and understand what caused it, if you carefully examine the plant. You should pay attention to how the yellowing occurs and whether there are other changes in the leaves.

The causes of chlorosis can be infectious and non-infectious.

Infectious chlorosis

Infectious chlorosis is caused by diseases: yellow mosaic virus, ascochitis, green mosaic, bacteriosis.

Yellow mosaic virus: first, the veins turn yellow throughout the leaf, then yellow strokes appear, after a while the entire leaf turns yellow. The leaves dry up and fall off.

The causative agent of the disease is found in the soil, is carried with contaminated tools or insects.

Ascochitosis: first, light yellow spots appear on the foliage, which instantly turn brown, and after a while turn black. All other parts of the plant are also affected. Cucumber fruits are deformed. The cause of the disease is seeds collected from a diseased plant.

Green mosaic: chaotic yellow and light green spots are formed on the leaf. The edges of the sheet are bent down, the plate becomes wrinkled. The same thing happens with fruits. They become stained and shriveled.

Bacteriosis: irregular spots appear on the leaves of cucumbers. The color is yellowish at first, then brown. The pathogens live on plant debris. They are activated when the temperature changes abruptly.

Non-infectious chlorosis

Non-infectious chlorosis is caused by improper soil composition, climatic conditions, or poor maintenance.

Causes of non-infectious chlorosis:

  • lack of sunlight, which happens if the beds are located near a building or dense trees
  • with thickened cucumber plantings, when the lower leaves are closed by the upper ones
  • when planting is compacted, when the roots do not have enough space for development, and there is not enough nutrition
  • violation of watering. Chlorosis can be both with insufficient watering, and with excessive
  • hot weather
  • lack of trace elements in the soil.

With a lack of nitrogen, the leaves turn yellow completely, and the young shoots become thin. The fruits slow down growth, the tips of the cucumbers are sharpened.

With a lack of magnesium, only the veins remain green, the rest turns yellow. The leaf plate becomes thin, as if dried out. Fruits overripe quickly, they are not eaten.

With a lack of iron, the leaves at the top of the plant turn yellow.

Leaves turn yellow unevenly and with spots

Irregular spots scattered throughout the leaf often indicate a fungus or infection. Sometimes these are sunburns, but if you water the seedlings correctly in the evening or early in the morning, then this possibility is almost impossible.

- Powdery mildew appears in round yellow spots with a white bloom on the back of the leaves. Over time, these same leaves will begin to darken, dry out and die off. It is completely impossible to get rid of it - the plants will have to be destroyed in the fall.

But you can contain the spread of the problem and harvest a normal healthy crop. To do this, temporarily stop watering the seedlings and after a week treat it with fungicides or special medications. Process it regularly until the beginning of fruiting, but strictly observe the dosage on the package.

- Blurry yellow spots with brown blotches indicate anthracnose. Its other symptoms are the appearance of pinkish pads on the leaves and defects on the lashes.

Why do cucumber leaves turn yellow? What to do

When growing cucumbers, every gardener was faced with the fact that the leaves of cucumbers turn yellow. Now let's try to figure out what the reason is.

Cucumbers are delicate, capricious plants that require skillful care for them. You can help plants only when the cause of the yellowing of the leaves is correctly identified.

If the leaves of cucumbers begin to turn yellow, not only the lower ones, but also the ovary, it means that there is not enough light, the leaves also begin to turn yellow and the ovary falls off with sharp fluctuations in temperature during the day or at night.

With improper watering, if not watered for a long time or with excess moisture, watering with cold water, the leaves also begin to turn yellow. You need to water only with warm water in the evening, during the day in the heat, the leaves can get sunburn when watering.

Also, the yellowness of the leaves may be due to a lack of nutrients in the soil, since we often water cucumbers and macronutrients are washed out of the soil and they are not enough for the further growth of vegetables.

By the color of the leaves, you can find out how to feed the plant. If there is not enough nitrogen, the leaves become small, turn pale, then turn yellow.

And with a lack of potassium, a yellowing border goes along the edges, and then it dries.

Pour a solution of onion peels. To do this, boil it for 10 minutes, and then dilute it with water, add ash, and water it. You can also feed with infusion of herbs, add infusion of chicken droppings there and water.

With powdery mildew, the leaves of cucumbers turn yellow and curl.

To cure the plant, you need to treat its leaves with a 1% solution of burgundy liquid.

Thus, we considered all the reasons why the leaves of cucumbers turn yellow, as well as ways to cope with this problem.

Cucumber leaves turn yellow on the balcony

On the one hand, aggressive influences from the outside are minimized. On the other hand, in the case of young seedlings in boxes, several specific factors appear.

- In a closed glazed room, the same greenhouse effect appears as in a greenhouse. Therefore, the reason may be high humidity around, so open windows regularly.

- Leaves turn yellow if the boxes and pots are too tight for the cucumbers. Young plants grow rapidly and the root system needs more space. Then you need an unscheduled transplant of seedlings.

- Be sure to follow the seedling feeding schedule before and after the pick. After the appearance of the first leaves, use mineral fertilizers with nitrogen, and before planting with potassium.


Preventive measures allow you to avoid many of the problems associated with yellowing foliage. Prevention includes:

  • thoughtful choice of a place for cucumber plantings (crop rotation, illumination of the site, soil composition should be taken into account)
  • buying seeds only from trusted suppliers, disinfecting them before planting
  • keeping the distance between plants
  • watering with warm water
  • timely fertilization.

By following simple agronomic techniques, yellowing of cucumbers can be avoided.

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