Why do cucumber leaves turn yellow and what to do about it?

Many gardeners are faced with the problem of yellowed leaves of cucumbers: this crop can be very capricious to care for. There are many reasons why this happens - from incorrect planting dates to exposure to fungal microorganisms.

How to get rid of yellowness on leaves and save the harvest? A detailed guide to action is in our article.

Causes of yellowing cucumber leaves

The problem is caused by numerous factors: improper watering, lack of nutrients, damage by diseases and pests, unfavorable weather conditions.

Mistakes when watering

Cucumbers may lack moisture or have too much moisture.. Plants require different amounts of water depending on their growth phase.

Reference. Before fruiting begins, vegetables are watered every 3-4 days. Afterwards - more often, after 1-2 days.

In hot weather, cucumbers are irrigated abundantly every day, and in rainy weather, watering is reduced so that the bushes do not rot.

Sunburn

If drops of water fall on the leaves, they act as a lens through which the sun's rays burn the plant. As a result of burns, the leaves turn yellow and curl.. Therefore, when watering, especially in the heat, the foliage is lifted and the soil is moistened at the very roots.

Low temperatures

Adequate heat is important for cucumbers to grow.. Summer in central Russia, and even more so in Siberia and the Urals, is not always hot: at low temperatures, the development of the crop stops and the leaves turn yellow.To prevent this from happening, cucumbers are covered with film or other non-woven material during cold weather.

Fertilizer shortage

Depending on the location of yellowing of the leaves, the lack of one or another nutritional element:

• if the leaves turn yellow evenly along the edges, the plant does not have enough potassium - it is added to the soil when the fruits ripen for their normal growth and development;
• uniform pallor indicates a lack of nitrogen - it accelerates the growth of green mass, so it is fertilized with seedlings or added to the soil after rooting;
• the leaves turn yellow, but the veins remain dark green - there is not enough iron or manganese, the problem is solved by root feeding with a solution of iron sulfate and a solution of manganese, respectively.

Root damage

If the root system of cucumbers is damaged, it does not supply the bushes with nutrients at full capacity and the leaves begin to turn yellow. Therefore, seedlings are carefully planted in the ground, and care is taken when loosening and weeding.

Diseases

Even with proper care, cucumbers are susceptible to diseases.

The most common ones:

• powdery mildew - a white coating appears on the leaves in the form of spots similar to flour;
• root rot - part of the root dies, then the entire root system withers, the stem becomes thinner;
• anthracnose — yellow-brown spots and a pink coating appear on the green mass, the bushes quickly darken, the fruits wrinkle;
• peronosporosis (downy mildew) - manifests itself as yellow-green spots and a light green coating on the upper part of the leaves.

If signs of the disease are detected, get rid of it as quickly as possible. Among the universal and most effective drugs are Bordeaux mixture, Fitoverm, fungicides (remedies against fungal diseases) HOM, Fundazol, Previkur.

Poor pollination of cucumbers

Most often this problem occurs in greenhouses, since many varieties need insects for pollination. In warm weather, the doors of the room are kept open to provide access to plants for bumblebees and bees.

Reference. The attention of insects is attracted by honey plants (basil, catnip, snakehead), which are planted next to cucumbers.

Why do leaves turn yellow and curl?

If the leaves not only turn yellow, but also curl, are deformed, this indicates serious problems.

The lower leaves turn yellow

Often the lower leaves change color not as a result of improper care or disease, but from old age. Plants devote more energy to the upper leaves and fruits.

Other reasons causing this problem:

• lack of lighting;
• hypothermia;
• improper watering;
• fungal infection;
• deficiency of minerals (potassium, magnesium, phosphorus).

Leaves and ovaries turn yellow

It happens that the green mass changes color along with the ovaries. In order not to lose the entire harvest, it is important to identify the cause of yellowing in time:

• overload of ovaries;
• lack of sunlight;
• low temperatures;
• lack of nutrients, usually potassium and nitrogen.

The edges of the leaves turn yellow

There are several reasonswhy the leaves turn yellow and dry around the edges:

• illness;
• lack of moisture;
• lack of micro- and macroelements.

Seedling leaves turn yellow

Basically the reasons for this are the same as in adult plants, but there are also specific ones:

• waterlogging or lack of moisture;
• lack of fertilizers (after the appearance of 2–4 leaves, the seedlings are fed with a complex nitrogen composition);
• containers too small for seedlings.

How to save the harvest

The principles of cultivating cucumber bushes vary depending on from the place where vegetables are planted.

In the greenhouse

Growing cucumbers indoors, carefully follow the rules caring for them:

1. Temperature. Optimal values ​​are maintained at +20…+22°C during the day and at least +16°C at night. Soil temperature - +16...+18°C.
2. Watering mode. Cucumbers are moisture-loving plants; they require regular irrigation, especially in hot weather. Do not use cold water for this: it is preheated in the sun. It is important not to overwater the vegetables, otherwise the roots will rot and they will no longer be able to be restored.
3. Feeding. Along with moisture, cucumbers absorb from the soil the substances necessary for growth and flowering. When the soil is depleted, the growth process stops, the plant weakens, and the risk of disease increases. To prevent this from happening, fertilizers are applied to the soil in a timely manner. The soil is being prepared in advance, 2 weeks before picking seedlings or sowing, adding 1 m² 25 kg of manure or 10 kg of compost, 40 g of superphosphate, 40 g of potassium sulfate, 15 g of magnesium sulfate. Afterwards the bed is well moistened. After a week, add 30 g of ammonium nitrate per 1 m², dig it up again and spill it with water. on If the soil is prepared in the fall, then it is enriched with manure, in the spring - with humus or peat.

In the open ground

To collect a rich and high-quality harvest of cucumbers from the garden, follow simple rules for caring for crops:

1. During frosts and cold spells The culture is covered with film to prevent hypothermia.
2. Cucumbers on time wateredwithout allowing the soil to dry out or become waterlogged.
3. Plants treated for pests. For aphids, use a solution of ash; for ticks, use an infusion of onion peels. Dill is planted in the beds: its flowering attracts ladybugs - natural enemies of aphids and other harmful insects.
4. If cucumbers are planted in the same places, they will be planted on time fed with mineral and organic fertilizers to replenish nutrients.

Preventive measures

Prevention will help avoid yellowing of cucumber leaves:

1. The earth is mulched: This will retain moisture and warmth. Hay, straw or dried grass are used as mulch. The main thing is the absence of seeds and rot.
2. Do not allow dense planting cucumbers so that all leaves have enough sunlight. It is not advisable to plant the crop in the same place every year.
3. Follow the rules of crop rotation: ideal predecessors are onions, cabbage, legumes, root vegetables. It is not recommended to plant cucumbers where zucchini or pumpkins grew.
4. Culture fertilize regularly to preserve fruit quality and increase yield.
5. The bushes are sprayed a solution of potassium permanganate, soda or ash infusion.
6. Recognize signs of disease in a timely manner and pest damage: these problems are easier to prevent at the very beginning.

Advice from experienced farmers

In addition to chemicals, gardeners use folk remedies to combat yellowing and wilting of cucumber foliage:

1. Ash solution. To prepare, take 700 g of ash per 10 liters of water and leave for 2 days. Spray cucumbers 2-3 times a month.
2. Potassium permanganate solution. At the first symptoms of yellowing, the bushes are sprayed with a weak solution of potassium permanganate.
3. Soda solution. For 10 liters of water take 1 tbsp. l. soda, the solution is watered at the roots of the plants to get rid of fungal diseases.
4. Onion infusion. Add 100 g of onion peel to 10 liters of water, bring to a boil and leave overnight under the lid. In the morning, filter and dilute in a ratio of 1:4. This universal solution is sprayed on the leaves and watered under the bushes to prevent pests.
5. Cow dung infusion. Mix 3 kg of manure with 10 liters of water, leave for 3 days, then filter and dilute in a ratio of 1:3. Used for spraying and as root feeding. The product helps well in the fight against powdery mildew.
6. Milk serum. For 10 liters of water take 2 liters of whey or kefir. The composition is sprayed on the bushes. If you add 100 g of sugar to the solution, the product will speed up the ripening of the fruit.

Conclusion

Compliance with simple rules for watering, crop rotation, and timely application of fertilizers reduces the risk of spoilage of cucumber leaves and increases productivity. The most effective method of combating yellowness on leaves is prevention: do not overcool the bushes, systematically destroy weeds, remove all plant debris after harvesting, and disinfect the beds. Then you won’t have to use harmful chemicals to process cucumbers.