Cucumber leaves turn yellow - how to fight?

Often gardeners are faced with the fact that cucumbers turn yellow and dry the leaves. Many sin on insufficient watering, but in fact there may be several reasons for this. Let's figure out why this is happening and what to do to correct the situation and save the harvest.

Cucumbers. Illustration for this article is used under a standard license © ofazende.com

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Why do the leaves turn yellow

The most common causes for cucumber leaves to turn yellow are:

1. Broken watering schedule. Cucumbers are water-loving plants, but excess moisture is also dangerous for them. If they are watered too rarely or with insufficient water, the ends of the whips and leaves may begin to dry out. If poured, decay will begin (and sometimes it also begins with pale and yellowish leaves). Normally, you need to pour water so that the bed is wet by at least 10 cm, and at this depth the soil is moderate humidity: when squeezed, a lump would form that does not tend to crumble, but excess water from the lump would not flowed.
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2. Lack of nutrients. Yellowing of the leaves with moderate watering indicates that the plant clearly lacks nitrogen in the soil.
3. Frostbite. If the plants are frozen, or the nights were simply too cold, the leaves begin to fade.
4. Sunburn. With daytime watering, water droplets sometimes work as lenses, focusing the sun's rays, which leads to burns. To avoid this, watering is carried out early in the morning or in the evening, at dusk.
5. Disease. Usually yellowing of the leaves indicates fusarium, but there may be another disease.
6. Roots are damaged. Unsuccessful weeding, pests in the soil - and injured roots cannot provide the plant with the required amount of nutrition. To survive, the cucumber begins to get rid of the excess, and this excess usually turns out to be weak leaves.

Leaves curl and turn yellow

If the yellowness is "complete" with deformation and curling of leaves, this usually indicates the following problems:

1. Nitrogen deficiency. If the leaves are long, the leaf plate is underdeveloped and twisted downwards - the plant must be urgently fed with nitrogen or complex fertilizer.
2. Powdery mildew damage. This fungal disease manifests itself in the early stages in the form of pale and twisted leaf plates. You can fight it using regular airing of the greenhouse and treating the plants with a solution of Bordeaux liquid or copper sulfate.
3. Pests. Examine the leaves carefully - there may be a colony of spider mites or aphids on them. Spraying with pesticides of the appropriate profile will help.
4. Viruses. If all the rules of care are followed, but the leaves are curled, it is possible that this is a viral disease. Nothing can be done here - just destroy the affected plant until the infection spreads to the neighboring bushes.
5. Hypothermia or burns. Often the leaves turn yellow and curl if they touch the wall of the greenhouse heated from the sun, the cold glass in the greenhouse. Here you just need to make the garter so that they do not touch them.
6. Air is too dry. If there is not enough moisture, the cucumber reduces evaporation due to the smaller area of ​​the leaves - and they curl. Watering and humidifying the air will help.

Yellowing of the lower leaves

Specifically, the lower leaves usually turn yellow first: they, as the oldest parts, are least important to the plant. This is where the problems first appear:

1. Lack of lighting. If the leaves at the bottom are shaded by the upper "brothers", they become useless, and the cucumber gets rid of them by itself. You can solve the problem by correctly placing the lashes on the trellis - or just wave your hand: if there are enough leaves, let the lower ones dry out.
2. Lack or excess of moisture. We have already spoken about them.
3. Hypothermia. The lower leaves are closer to the ground, and the cold air goes down.
4. Lack of potassium, magnesium or phosphorus. The situation can be corrected by complex feeding.
5. Fungi. Fusarium, pityiasis and other diseases of a fungal nature primarily affect the lower part of the plant. The scourges also begin to dry out, become lethargic and loose. The affected part of the plant must be cut off immediately and burned.
6. Old age. If the leaves turn yellow underneath at the end of the season, this usually means that the cucumber has begun to die off. This is a natural process that you can't do anything with. We must prepare for the autumn cleaning of the site.

Leaves and ovaries turn yellow

If not only the lower, but also the upper parts of the plant, together with the ovaries, have strangely turned pale, it's time to take action. There may be several reasons:

1. Insufficient illumination. It is not scary for the lower leaves, but if there is not enough sun for the upper ones, something must be done - right up to the installation of a phytolamp.
2. Hypothermia, especially if the hot weather is suddenly replaced by cold and rain.
3. Lack of nitrogen and potassium. These substances are easily washed out - and cucumbers just need frequent watering. Feed the plants with compound fertilizer.

Yellowing of the edges of the leaves

If only the edges of the sheet plate have turned yellow, this may indicate the following:

1. The first phase of powdery mildew. It's time for a spray bottle with Bordeaux liquid (1% solution is enough, overdose is fraught with chemical burns).

1. Little moisture. If the air and soil are dry, the plant begins to lose moisture from the tips of the leaves. Observe the watering regime.
2. Lack of potassium. If there is a yellowish-blue (light green) border along the edge of the plate, feed the cucumbers with potassium nitrate or something similar.

Yellowing of leaves in the greenhouse

Specifically in the greenhouse, yellowing of cucumber leaves is usually associated with the following factors:

1. Violation of the watering regime. When the cucumbers are blooming and giving an ovary of zelents, it is necessary to water every 2-3 days with a bucket of water per square meter of the greenhouse. If the weather is cloudy, less water is needed, on hot days a little more. Check soil moisture at a depth of 10 cm. If the soil there is wet, watering is not needed yet.
2. Uncomfortable temperature. Normally, before the ovaries appear in the daytime in the greenhouse, it should be 22-24 degrees, when it is clear, 20-22 - when it is cloudy, at night - 17-18 degrees. When the cucumber bears fruit, in clear weather it should be from 23 to 26 degrees, and in cloudy weather - from 21 to 23 degrees, at night from 18 to 20 degrees.
3. Lack of fresh air. Ventilate the greenhouse regularly. At the same time, reduce the risk of fungal diseases.
4. Lack of food. Fertilize your plants regularly.
5. Possible diseases or pests. For prevention, at least once treat the planting with Bordeaux liquid from fungi, nitroammophoska solution from aphids and colloidal sulfur from spider mites.
6. Thickened planting. Observe the seeding rate, do not try to stick too many plants in a small area.

Caring for cucumbers in the garden

To prevent leaves from turning yellow in plants outdoors, follow a few rules:

1. Cover in cold weather with foil, agrofiber or other material.
2. Observe the watering rate. If the soil is dry, water it, if there is an overflow, immediately loosen the soil and sprinkle it with ash and coarse sand so that drainage appears.
3. Fertilize regularly.
4. Lead disease prevention and pest control. Examine the plants and apply the correct medication if signs of damage are found.
5. Do not water cucumbers in the sun to avoid scalding.

Yellow spots on cucumber leaves

If yellowness has gone in separate areas on the leaf plates, this is usually a sign of a fungal disease. Here are the main ones:

1. Anthracnose. The symptom is vague, round spots prone to pink pads. Also, with it, elongated small ulcers appear on the stems. Treatment - with a suspension of colloidal sulfur, then after a week and a half - Bordeaux liquid. The affected areas are treated with a swab dipped in a 0.5% solution of vitriol and powdered with crushed coal.
2. Downy mildew. Spots appear on the upper side of the leaf, and the lower is covered with a whitish bloom. Leaves dry quickly and die off. Treatment - "Oxyhom" (20 g per bucket of water) or "Consento" (40 ml per bucket of water). But this will only allow you to contain the disease and get a harvest. In autumn, dry tops must be burned. It will be possible to plant cucumbers on this plot no earlier than in 6-7 years.

Folk remedies

To avoid problems with yellowing of cucumber leaves, you can use the following infusions:

1. In a bucket of water, you need to pour 1 liter of milk (preferably homemade), 20 g of shavings of laundry soap and 30 drops of medical iodine tincture. The composition is mixed until smooth, and then cucumbers are sprayed with it every 10 days from the moment the second pair of leaves is formed.
2. A loaf of stale bread is dipped into a bucket of water for the night. In the morning she warms up, a bottle of iodine tincture is poured in, everything mixes well. The finished composition is diluted with clean water in a ratio of 1:10 and used for spraying once every two weeks.
3. 1 liter of dry onion peel is poured with a bucket of water and brought to a boil. After that, the composition is closed with a lid and insisted for 14 hours. The finished product is diluted with water four times, the leaves are sprayed with it, the remains are poured under the roots.

Top dressing for cucumbers

To avoid yellowing, the cucumbers must be fertilized properly. The following formulations work best:

1. Complexes "nitrogen-phosphorus-potassium". It is best to use ready-made mineral mixtures, but you can prepare them yourself by dissolving 10 g of superphosphate and the same amount of potassium salt and ammonium nitrate in 10 liters of settled water. The ready-made mixture should be used only for root dressing. For foliar, the solution must be diluted at least 4-5 times, otherwise the composition will burn the leaves.
2. Herbal infusions. Comfrey infusion is best suited: a kilogram of fresh herbs is poured into 10 liters of water, closed and insisted for a week in a warm place, then filtered and diluted in a 1: 9 ratio. The infusion of young nettle is also good. It is prepared in the same way, only 500 g of green mass is put. Such fertilizers are suitable for watering and spraying. After application, it is good to powder the ground at the roots with wood ash.
3. Urea (urea) solution. 40 g of the drug is dissolved in a bucket of water and used to spray the plants. At the same time, organic matter is introduced under the roots - compost, humus, vermicompost.

We hope these remedies help you avoid cucumber problems.

Do you know why cucumber leaves turn yellow and dry?

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