Why do cucumber leaves turn yellow in a greenhouse and what to do about it

22.07.2016 Cucumbers Diseases and Pests Greenhouse

Unfortunately, it is not so easy to understand why the foliage on these plants begins to turn yellow, because there are too many reasons, so we will analyze several cases to find out how to deal with yellowing of the foliage. There are several effective ways to help prevent yellowing of the foliage, as well as improve their appearance if the tops of the cucumber still began to turn yellow. There are different ways to plant potatoes for an excellent harvest.

Not enough light

If the greenhouse is improperly equipped, then the plants may not have enough natural light in it, in this case the leaves begin to turn yellow and thin out, and then fall off. It is not necessary to worry that only the lower leaves began to fall and turn yellow, because in the overgrowth of greenery the light can not always go in abundance to the leaves located closer to the ground. If yellowing occurs precisely because of insufficient lighting, it is enough to eliminate the leaves that are already yellowed, but there should not be a lot of them.

Too much moisture or lack thereof

The reason why the leaves of cucumbers turn yellow in the greenhouse, and how to deal with it (video), can be very simple, because every plant loves water, but only in moderation. If less moisture than necessary is introduced into the soil, the leaves will begin to turn yellow and dry out, in the case when the humidity is greatly exceeded, the foliage may simply turn yellow.

Why do cucumber leaves turn yellow in a greenhouse and how to deal with it

I would like to note that with insufficient watering the plants are more drawn to the soil, and this leads to yellowing of the leaves, as well as the drying of new ovaries. Excess moisture can occur not only with frequent watering, but also due to heavy and long rainfall, in this case, a grill appears on the roots, it extends not only to the stems, but also to the foliage. Water correctly cucumbers in a polycarbonate greenhouse on a typical summer day, not more than three times a week, if the weather is dry, the cucumbers will need daily watering.

Fungal infections

Fungal diseases can lead to the appearance of yellow leaves on plants, and they also affect the future crop of cucumbers, so it is necessary to take measures to destroy the fungus in the ground, before planting the plants. Fusarium can become the most common type of damage to cucumbers, this fungus affects foliage and the whole plant as it penetrates the cucumbers through the roots. First, on the greens, you can notice small spots, similar to rust, after a while all the leaves are covered with such spots, they begin to quickly dry out and fall off.

It is not so difficult to learn about this disease if the new lashes become lethargic and dehydrated, and after watering no positive dynamics are noticed, this will indicate the presence of a fungal disease. Most often, fungal diseases affect plants when there is a noticeable change in temperature from hot to cold, as well as if the soil has been excessively wet due to hot weather. In this case, it is necessary to identify as quickly as possible the reason why the leaves of cucumbers in the greenhouse turn yellow, and how to deal with it on your own, without resorting to the use of chemicals. Diseases of cucumbers in a greenhouse need to be treated on time, otherwise the plants may die.

The appearance of pests on the site

In some cases, the yellowness of the leaves can tell about the appearance of pests in the greenhouse. The most common and dangerous for cucumbers are whiteflies and spider mites, these two insects begin to feed on plant juices, and since whiteflies lay eggs in large numbers, the larvae can destroy the crop in a few days. In this case, it is worthwhile to carry out preventive actions to eliminate pests from your site in advance, if this still does not help, it is recommended to purchase strong toxic substances that will save the crop. When insects just started to take root in cucumbers, one can also try popular methods of destroying “uninvited guests”.

Not enough nutrients in the ground

This reason why the leaves of cucumbers turn yellow in the greenhouse, and how to deal with it, is one of the less common, but in some cases the lack of nutrients affects the leaves and plants in general. For example, when yellowness on the edges begins to appear on the leaves, this will indicate an insufficient amount of nitrogenous substance in the soil, as well as a possible lack of potassium. When the entire leaf turns yellow, and dark greens appear on the greens, this will become a clear sign of a deficiency of manganese or iron, but the upper leaves begin to turn yellow if there is little copper in the soil. Correcting the situation is quite simple if you feed the plants with the necessary fertilizers. For example, the most popular fertilizer that our readers use is this tool. It will help to grow not only cucumbers, but also many other plants.

The sixth reason will be old age

Over time, the leaves of cucumbers begin to acquire a yellow color, this is quite normal if the period of growth and fruiting is already nearing completion. But there are several ways that help extend the life of lashes, as well as improve the yield of cucumbers, but this will be written later.

Prevention of yellowing of leaves

In order not to come across the question of why the lower leaves of cucumbers in the greenhouse turn yellow, and how to deal with it, it is necessary to carry out preventive methods that will help to avoid diseases and other troubles with cucumbers in greenhouses. The fact is that it will be easier to prevent such situations than to correct them later.

The first rule includes proper sowing, because you can’t sow cucumbers in one place every year, this only increases the chances of diseases. It is also not recommended to plant these plants after growing zucchini and pumpkin, it is these vegetable crops that can leave behind fungi, which, with the onset of spring, will develop at a tremendous speed and will affect all plants.

The second rule will be compliance with watering, because the soil must be moistened constantly and sufficiently. When the gardener visits the site exclusively on weekends and holidays, he should apply the mulching method. Closed beds will be wet for a long time, as grass laid on top of the soil will not allow water to evaporate. Mowed grass will help provide roots with additional nutrients.

The third rule is to properly fertilize the plants, cucumbers need periodic top dressing with minerals, as well as organic top dressings. Herbal tincture is considered one of the most effective top dressings, and to make it simply in your kitchen, before watering the plants with such top dressing, ten grams of ash are poured into the hole. The crushed granules of ash effectively fight harmful insects that infect plants in the beds, and this substance also helps to add potassium to the soil, which plants use for growth and fruiting. You will also probably be interested to know what to do if cucumbers do not grow.

Cucumbers need specialized watering, it is carried out in a certain growth phase (3-5 leaves have already appeared at the posts), spraying is repeated every ten days before the start of the fruiting period. For the solution, twenty grams of grated laundry soap are taken on a grater, it is poured into a liter of heated milk, exactly thirty drops of pharmacy iodine are added, and the composition is mixed with ten liters of pure water.

For preventive spraying, you can use other methods, for example, it is enough to prepare a special solution, it is made from a white loaf. To begin with, the bread is soaked in one bucket of clean water, when in the morning the bread is well soaked, knead it to pulp and add to the solution a full bubble of pharmaceutical iodine. It is impossible to use this solution in its pure form, therefore exactly one liter of this product is taken on a bucket of water, and then beds with cucumbers are watered with it. If the gardener can repeat the process every fourteen days, he will keep the greens and ovaries healthy and green until the fruiting period.

When June comes, you can start the following types of protection, for this they use an alkaline solution of water and soda, for it you will need ten liters of clean water for irrigation, as well as one large spoon of soda. If you water the plant with a remedy, then the fungi will not be able to take root in an alkaline environment, but the vegetables will feel great. Onion husks are deterred by pests, if the gardener is faced with the question of why the leaves of cucumbers turn yellow in the greenhouse, and how to deal with it (photo), he should learn the recipe for preparing a solution of husk from onions.

To do this, take a liter jar, put onion husks to the edges, pour the resulting amount into a bucket of water and put on fire, as soon as the mixture boils, turn off the fire, put a lid on the bucket and leave it for at least twelve hours. After the allotted time, the broth is filtered through a sieve, and then diluted with clean water two to eight, the leaves of the plant are sprayed with the mixture on one and the other side, and the soil is also watered with cucumbers.

When yellowness has already appeared on the leaves, another solution can save the situation, it is prepared from whey or kefir, two liters of the drink are diluted in one bucket of water, and in order to better tie the fruits, add half a glass of sugar to the resulting mixture. Next, the leaves are sprayed with the resulting solution.