At what night temperature do cucumbers grow in open ground and in a greenhouse?

At what temperature do cucumbers grow in open ground at night?

Why at night? Because it is at this time of day that the fruits receive nutrients from the leaves. In open ground, at high temperatures, fruits will grow more actively, and at moderate temperatures, the shoots and roots of the plant will grow more actively.

The best option here is the golden mean. The temperature between day and night should not differ by more than 7°C.

What causes the bitterness of cucumbers?

The bitterness is caused by a substance called cucurbitacin produced by the plant.

The degree of bitterness is highly dependent on sunlight: the brighter the sun, the more bitter the fruit is.

In their historical homeland, cucumbers climbed trees and hid their fruits in the shade.

Prolonged exposure to sunlight reduces air humidity, deprives the cucumber plant of its usual environment, and it, in defense, intensively produces cucurbitacin.

Optimum temperature for night growth of cucumbers

Seeds germinate at +10-12°C, and leaves and the fruits themselves form at +15-16°C. If you decide to increase the temperature during seed germination to +25°C, the process will go much faster, and sprouts will appear 5-6 days after sowing. If you increase it to +17-20°C, expect shoots on the tenth day. Carefully monitor the temperature drop; if it drops below +10°C, the sprouts will turn yellow and die.

As for soil temperature, a lot depends on the cucumber variety. Each has its own optimal germination temperature. The average favorable soil temperature at night is +16–18°C. But the seeds will germinate faster if the air temperature is slightly lower than the soil temperature.

Preparing a place for growing cucumbers

The place where cucumbers are planted must be protected from the winds.

If the site is too windy, it is artificially protected by planting sunflowers, beans or other tall crops.

The plot for cucumbers begins to be prepared in the fall.

The soil is dug up on the bayonet of a shovel, while the clods of earth do not need to be broken so that moisture is retained in them.

If you have loose soil, then it is advisable, of course, not to dig it up, in order to preserve the vital activity of beneficial microorganisms in it, which will help increase productivity.

Cucumbers are very fond of organic fertilizers , such as manure, compost or peat, which are applied to the soil in the fall at the rate of 4-6 kg per square meter.

If the soil is poor, the amount of fertilizer applied can be safely increased.

Minimum and maximum permissible temperature

The maximum permissible temperature for cucumbers is +42°C. Already at +35°C problems with fruiting begin. The ovaries dry out and fall off, spider mites appear, and the pollen becomes sterile. High temperatures contribute to the aging of canes, as the root system reduces its absorption capacity.

To ensure that cucumbers do not die in abnormal heat, it is necessary to additionally irrigate not only the beds themselves, but also the areas adjacent to them. And sprinkling contributes to less surface overheating of plants and additionally cools the soil. If possible, cover the trellises with light, light agrofibre.

Summer residents are also worried about the overcooling of their plantings. Most often this happens if there is a north wind in the region. The difficulty of open ground is that achieving constant warmth is problematic, but gardeners use some tricks that help maintain comfortable conditions:

1. Cucumbers are planted along the walls of buildings on the leeward side, but where the sun's rays fall.
2. Cucumber trellises are placed between rows of plants with tall stems. Thanks to the “walls,” the temperature becomes several degrees higher and creates additional shade, but in the south this method is not popular, as it can lead to overheating of the cucumbers.

Important ! In most cases, bush plants take away some of the moisture, so watering cucumbers in such a neighborhood should be treated with special responsibility.

As for the minimum temperature, at temperatures below +10°C the root system stops absorbing nutrients from the soil. As a result, the plants begin to starve and are susceptible to various diseases. If the low temperature (below +3...+4°C) persists for three days, the plant tissues begin to deteriorate, as a result of which the cucumbers die. If seeds are sown in frozen soil, they will not sprout until it warms up well. Active growth stops at temperatures below +15°C.

The night temperature regime for growing cucumbers should be without sudden changes, as this will lead to a decrease in yield. If temperature fluctuations in your region are sharp, and night temperatures are below favorable for cucumbers, grow them in a greenhouse or greenhouse.

Watering cucumbers

The main requirement for cucumbers is water; they need to be watered constantly.

But do not overdo it, because cucumbers do not like waterlogged soils for various reasons.

One reason is the easy occurrence and spread of pests such as powdery mildew.

When the soil dries to a depth of 2-3 centimeters , it means it’s time to water the cucumbers.

Inconsistent watering causes cucumbers to become bitter.

Cucumbers should be watered in the morning.

Try not to get water on the leaves to avoid causing leaf diseases, which can later destroy the plant.

Therefore, it is very convenient to water cucumbers with a hose or using drip irrigation.

When seedlings appear, the frequency of watering needs to be increased.

What to do if the temperature is below normal

There are several ways to help save your cucumbers from prolonged frosts. The most common way is to build a warm or manure bed.

dung ridge

At low temperatures, it will provide the plant with warmth and the necessary nutrients for growth. Do it carefully, as the active burning phase can have a bad effect on young plants.

A bed of manure is prepared 14 days before sowing the seeds. To do this, place the manure in a high bed and water it. Polyethylene will speed up the combustion process.

Steam from the ridge means it has started working. After two days of active burning, you can begin planting seeds in holes with soil. Pay attention to the thickness of the soil. It should be at least 30 cm. If there is a threat of frost, use film or spunbond (covering material). Cucumber vines that grew on manure are less likely to get diseases.

Warm ridge

This is almost the same as manure, but the biofuel used here is:

• food waste;
• leaves;
• branches;
• grass;
• tops

Note! If the seedlings are placed on an inorganic cushion and covered with film on top, then they will not be afraid of frost. This is also suitable for rainy summers, since organic matter is very humid and produces heat for the growth of cucumbers.

Advantages of warm ridges:

• arcs and shelters are easy to fix;
• the process of warming up the soil goes faster, and seeds can be sown earlier;
• there is less weed;
• drainage in the form of large branches will eliminate stagnation of water, which has a good effect on the development of the root system;
• organic matter begins to rot and warm the soil, which makes cucumbers grow better at night.

Arcs and covering material

Inexpensive kits for summer residents with plastic arches and covering material will help save cucumber vines.

Attention ! Installing arcs under the holes will protect the cucumbers from May frosts. Dense covering material will also help seedlings when cold weather sets in.

It is recommended to purchase white spunbond to protect the cucumbers from the spring cold snap. It is better to choose a density of 23 g/m². This is enough to protect the cucumbers from the cold and will also help them withstand strong winds.

If frost has damaged the leaves of cucumbers, use the drug "Epin". It will help when:

• the cucumbers are frozen;
• the leaves have turned yellow;
• It rains every day and gets colder;
• attacked by aphids or other pests.

Even with a single treatment with Epin, the plant’s immunity will be restored. Fertilizers should not be used for two weeks. It is also worth purchasing a growth stimulator.

You can restore cucumber lashes using other good means:

• "Zircon";
• "Narcissa";
• "Amulets";
• "Silka."

Fertilizers

Long low temperatures in summer have an adverse effect on cucumbers. The leaves at the tips begin to lighten, the ovaries form more slowly. In this case, they are fed with a solution of urea or urea.

Prepare this solution immediately before use. 1 tbsp. l. The drug is added to 10 liters of settled water. Dry and cloudy weather is suitable for processing cucumbers.

Reference ! You will need to save cucumbers using this method several times with an interval of 3 days until the leaves acquire a dark green color.

Traditional methods

If cold weather comes unexpectedly, but there is no covering material at hand and there is no time to make a shelter, folk methods will come to the rescue. Grass or branches can be torn and placed on top of the young cucumbers, and tied to the trellis, lowered a little lower. A layer of mulch will protect against freezing. In the morning, you can rake it out a little, but you shouldn’t remove it, as it will be needed so that moisture remains in the soil and it does not freeze.

Another option is to make shelters from roofing felt. They are removed in the morning, but at night they are good protection against frost.

Boric acid is also used as a rescue from low temperatures. A five-gram bag of powder is stirred in hot water and poured into 10 liters of water. When the sun sets, the cucumbers are sprayed with this liquid.

This treatment will not only save cucumbers from freezing, but will also make them more resistant to diseases: bacteriosis, powdery mildew, and root rot.

Predecessors of cucumbers

To grow cucumbers, you need to pay attention to crop rotation.

If you grow not only cucumbers, but also any other plant in the same place, you will get a decrease in yield.

Indeed, with this cultivation regime, the soil not only becomes tired, but also phytopathogens accumulate in it.

Therefore, it is recommended to grow cucumbers in the same place every 3-5 years.

The best predecessors of cucumbers: white cabbage, cauliflower, greens, legumes (except beans), potatoes, root vegetables (except carrots).

Temperature conditions for the growth of cucumbers in a greenhouse

Maintaining the temperature in the greenhouse is extremely important - this affects the development and growth of cucumbers, the quantity and quality of consumed nutrients.

Seedlings are planted at temperatures from +20 to +22°C. It is also optimal for further growing cucumbers in a greenhouse.

If we talk about the temperature of the earth, then in the greenhouse it should be no higher than +18°C and no lower than +16°C. To do this, you need to additionally cover the greenhouse at night.

When 7 days have passed after germination, the temperature should remain at +20°C. For more comfortable conditions, a small amount of outside air is allowed in. But you can’t remove the film completely. This can have a bad effect on the seedlings.

After 2-3 leaves appear, the greenhouse must be constantly provided with heat. The optimal temperature for this is +22-24°C.

Attention ! Temperature changes should be gradual, otherwise it will have a bad effect on young cucumbers.

Treatment of cucumbers

Cucumbers are very attractive to aphids and spider mites , so it is best to try to prevent and completely avoid the presence of these insects.

As organic antiparasitic agents prepared in the form of an aqueous solution, we recommend using garlic infusion and nettle macerate.

Cucumbers should be sprayed with these preparations at night.

It is necessary to generously moisten the lower part of the leaves, where aphids and spider mites are usually found.

Cucumbers are also highly susceptible to fungal diseases such as powdery mildew and anthracnose.

Powdery mildew is a white coating that settles on the surface of the plant.

This parasite often leads to crop loss.

Parts of plants affected by powdery mildew first turn yellow and then die.

Anthracnose is a pathogen that attacks stems, leaves and fruits.

Its appearance is accompanied by the appearance of yellowish and oily spots of 1-2 cm, which soon turn into necrotic areas of various sizes.

For both diseases, as a preventive measure, cucumbers are sprayed with an aqueous solution with sulfur powder.

Sulfur is a natural element, so its use is allowed in organic farming.

Spraying should always be done during cool daylight hours and repeated every 10-15 days.

In addition, sulfur powder, due to its pungent odor, is an excellent repellent for aphids and mites.

Therefore, its use also helps in the prevention of parasites.

Tips and recommendations from experienced gardeners

And finally, a few tips from experienced summer residents who know a lot about growing cucumbers:

1. Choose varieties that are least susceptible to disease.
2. After the first planting, the next seeds are planted after 4-5 weeks. This is necessary so that you can enjoy the harvest in late August or early autumn.
3. Always make sure that the soil of your cucumbers is slightly moist. This will protect them from the bitter taste.
4. To prevent insects from attacking your crops, cover the plants with translucent material until they begin to bloom and fruit.
5. Once the cucumbers are ripe, harvest them every few days. Make sure that the fruits do not turn yellow, as this takes away the strength for further fruiting.

Features of growing seedlings

1. In order to shorten the period before the fruit begins to appear, you can install ventilation windows in the greenhouse when the temperature is too warm. This is how young shoots harden and become stronger.
2. Optimum day and night temperatures should be observed.
3. Seedlings should be grown no longer than 30 days, after which they can and should be planted, otherwise, if grown for a long time, it will be difficult to transplant them to a permanent place of growth.
4. Irrigation is carried out only with heated water.

How many days does it take for cucumber seedlings to sprout?

The timing of the appearance of the first shoots in seedling cups is also closely related to the temperature regime. It’s one thing to plant hatched seeds in warm, heated soil, and quite another if the soil is still quite cool.

The optimal thermal regime – 25-28°C – is maintained for pots with crops around the clock. If everything is done correctly, the first tiny leaves will appear from the substrate within 7-10 days. If the temperature is about 20°C, seedlings will take from one and a half to two weeks. At a lower temperature (from 15°C) you may not wait for germination at all. In this case, sowing will have to be repeated.

Soil fertility also affects the timing during which seedlings emerge. The richer the soil in nutrients, the faster the sprouts appear.

Optimal conditions for a greenhouse

We figured out what the temperature should be for cucumbers at night in open ground. Now let's look at the values ​​​​for the option with greenhouse cultivation.

The containers in which the seeds are located should be left at a temperature of about 27 degrees. When you notice the first leaves, you can lower the mark to twenty-two.

During daylight hours, the room must be well ventilated. Various containers filled with water are installed around the perimeter. They guarantee ideal humidity.

Types of greenhouses and their features

Various materials are used as the basis for constructing protected soil, so the cost of greenhouses, their heat-saving characteristics, and service life vary significantly. The frame of greenhouses can be wooden or metal, differ in height and ability to withstand the weight of the covering:

Modern, durable, fairly lightweight material allows you to set up greenhouses for early spring use. They retain heat well when heated. Such greenhouses are not warm enough for winter use.

This covering material is quite heavy, so the frame must be strong. Glass greenhouses, with proper design and heating, can be used all year round.

They build both high greenhouses and low temporary protective structures. Lightweight material allows the use of a simple frame made of wood, polyethylene, plastic pipes and thick wire. Such greenhouses are intended for spring use after the ground has thawed, growing seedlings for open ground and obtaining earlier products.

Increasing thermal conditions

If, due to weather or other conditions, the temperature in the greenhouse has dropped and the created environment threatens the health of the cucumber bushes, to quickly increase the thermal temperature, use one of the techniques recommended by experienced summer residents.

1. Create an air layer that can protect cucumber plants from the harmful effects of the environment. This can be done by covering the planting with film for a short time.
2. You can reduce heat loss and stabilize the microclimate in a greenhouse by creating a so-called second greenhouse, which is built directly on the vegetable planting in the form of a wire frame or made of wooden structures and other handy materials. In this case, a perforated film is used as a covering material, ensuring proper air exchange and creating ventilation for ventilation.
3. You can increase the thermal temperature by mulching the soil. This is done using both organic matter and dark-colored film.

Features of crop irrigation

When planting material is in a phase of active growth under unfavorable climate conditions, an important step is harrowing the beds. As a result, the cucumber plantation grows in improved thermal conditions.

Between the completed beds, the air temperature rises to 4 degrees, in contrast to those areas that are not protected. And if crops are grown in conditions of elevated temperature, this measure will be an excellent protection against overheating of the seed material and emerging sprouts.

Thanks to proper irrigation, it is also possible to regulate climate indicators to a greater extent. In those areas where irrigation is carried out, there is a decrease in indicators to the low side. Especially if the soil has warmed up well before.

If there is a cold snap, plants are hilled above the first internodes. This garden crop is very sensitive to possible frosts. This plant can die even if frosts are short-term. If there are sudden changes in climatic conditions, cucumbers may die because they cannot withstand such stress.

Favorable growing temperatures

Favorable for growing plants are the average daily air temperature, slight daily temperature fluctuations, and a slow decrease in temperature at the end of the growing season.

Night temperatures for growing cucumber plants that fall below +15-+13 degrees lead to a decrease in cucumber temperature and a decrease in yield.

This pattern is explained by the fact that cucumber fruits grow mainly at night.

If the temperature and air humidity drop simultaneously, cucumber plants are affected by a fungal disease called powdery mildew.

Cucumbers grow most intensively in the temperature range from 20 to 30 ºС.

Different varieties have their own optimal temperature for best growth. Growing cucumbers will work better if the soil temperature is slightly higher than the air temperature.

Which soil should I choose?

If you decide to grow cucumber seedlings indoors, then it is important for you to prepare a suitable soil mixture for planting in advance.

There are many subtypes of soil on sale; there is also a variety of substrate designed specifically for growing cucumber seedlings, which makes the work of gardeners much easier. However, many more experienced farmers prefer to prepare the soil themselves in order to be sure of its quality and composition.

The substrate should be prepared in the fall. You can leave the soil in a cold shed or on a balcony until it is sufficiently frozen (this acts as a natural antiseptic). Next, you can begin preparing the substrate.

Cucumber seedlings - several soil mixture recipes:

• The easiest way is to prepare a soil mixture, which consists of turf soil, humus or compost mixed in a 1:1 ratio. Coarse sand should also be added to this soil. Add a glass of wood ash to one bucket of this mixture.
• Mix a bucket of garden soil with 3 liters of humus. Add superphosphate (1 tablespoon) and wood ash (1 cup) there. If the soil was initially too clayey, then dilute it with 2 liters of fine sand.
• Add a bucket of sawdust to 3 buckets of garden soil. Add 1 bucket of manure to the mixture. Mix everything thoroughly.
• For 2 buckets of garden soil, take 2 buckets of peat, a bucket of manure, 2 cups of ash and 2 tbsp. spoons of superphosphate. Mix everything well. If the soil initially had high acidity, then it is better to add 1 bucket of peat mixed with urea, superphosphate and potassium sulfate in a ratio of 1:1.5:2 matchboxes.

The nuances of preparing homemade soil:

• If you use garden soil as a base, then under no circumstances take it from under cucumber plantings or from beds where other pumpkin crops grew.
• Regardless of the composition, the seedling soil used must be breathable, absorb and retain moisture.
• Be sure to disinfect the finished soil in any way convenient for you before use.

How to care for seedlings?

Before the first shoots appear on the cucumbers, you should set the room temperature to +23..+25 degrees. You can simply move the planting containers with your seedlings to a warm place and cover the top of the boxes with glass or film.

IMPORTANT! Periodically lift the glass or film and ventilate the plantings. This will help avoid rotting.

If you carefully follow all the recommendations, the first shoots will appear in 3-5 days. If there are two or more shoots in one container, then leave only the strongest and healthiest one, pinch off or trim the rest. Under no circumstances should you pull the seedlings out of the ground - this can damage the rhizomes of the remaining plants in the container.

Temperature and lighting

Previously, we have already described in detail the temperature and light conditions for cucumber seedlings, so let’s briefly go over the main points again:

• As soon as the first shoots appear, you should immediately transfer the seedlings to a well-lit place. At the same time, the temperature is reduced to +19..+22 degrees during the daytime and to +15..+17 degrees at night. Do not leave plantings in a draft - they will not survive it!
• Daylight hours for cucumber seedlings should be at least 10 hours, but for better germination of seed and the formation of strong seedlings, it is better to increase it to 12-15 hours a day. If there is not enough natural light for plantings, then take care of artificial lighting.
• If you notice that the seedlings have begun to stretch out, and its shoots have become thin and weak, this means that the plant does not like the temperature or light conditions.

IMPORTANT! If you still could not avoid problems with cucumber seedlings, and they have become elongated, then you should take the elastic thin stem of the plant and carefully roll it into a ring, laying it on the surface of the soil and sprinkling it with soil on top (15-20 mm is enough) . Moisten these seedlings regularly. In a week, the shoot sprinkled in this way will give roots and further growth to healthy and high-quality seedlings.

Cucumber seedlings fertilization methods

Whatever growing location you choose, cucumber seedlings will need about 2-3 full feedings. Each of them is entered 14 days after the previous one is entered. Properly applied fertilizers guarantee strong and healthy plants. The first fertilizing is applied when the second full leaf appears on the plants.

Feeding options:

• Mix 15 g of ammonium nitrate (or 10 g of regular urea) in 10 liters of water. Add 25 g of superphosphate and 9 g of potassium sulfate to the mixture. For every 7-8 plants there should be a glass of this mixture.
• It is acceptable to use organic matter to feed cucumber seedlings. Mix 1 liter of mullein with 10 liters of water. Water the plants with the resulting solution. Instead of mullein, you can take bird droppings, but then the proportions will be slightly different - 1:15.

Fertilizer application rules:

• Do not use fertilizers containing chlorine. Cucumbers will not tolerate this.
• The application of all fertilizers should be combined with watering.
• Carefully wash off any remaining fertilizer from the leaf blades of the plants or water them so that the product does not get on the shoots and leaves.

Watering mode

The soil in planting containers with seedlings should always be moderately moist. As soon as the first shoots appear, watering should be somewhat more frequent. After the seedlings get stronger, you need to reduce the amount of liquid applied again. Watering should become more intense again after the appearance of the second strong leaf.

Water for irrigation should be at room temperature, but not lower than 25 degrees. Cooler liquid will slow down the growth of plantings and increase the risk of rotting of the root system.

Cucumbers before frost?

Cucumbers in open ground stop bearing fruit around mid-August. But there are rules that, if followed, can extend the fruiting period until frost. What to pay attention to. Sharp difference between day and night temperatures.
Temperature fluctuations have a negative effect on cucumbers. If the nights are cool, greenhouses should be closed, and in open ground they should be protected with covering material.

Lack of moisture.

Caring for cucumbers in a greenhouse and in open ground requires uniform, abundant moisture. With a lack of watering, the leaves on the cucumber vines curl and the ovary falls off. In the summer heat, cucumber beds should be watered daily. To prevent the soil from drying out too quickly, it is recommended to mulch it.

Lack of feeding.

Caring for cucumbers necessarily includes the scheduled application of fertilizers, because the plants spend a lot of energy on the formation of greens.

Pest invasion.

In the hot summer, in addition to drought, cucumbers are plagued by pests and diseases - spider mites usually attack plantings, so daily inspections are necessary: ​​the sooner it is detected, the faster you can get rid of it. Among diseases, cucumbers are usually threatened by powdery mildew; plantings need to be treated with fungicides.

cucumber vines should be

This is fastening to the trellis when the 8-10th true leaf appears; pinching the main trunk - when the length of the lash reaches 2 m, it is recommended to cut off the top; pruning side shoots - when the length of the lash reaches 50 cm. Up to 4-5 growth points are left on the main lash; pinching empty flowers and male shoots above the 3rd leaf; cleaning cucumber vines from damaged and yellowed leaves.

It is recommended to install several open containers with water in the greenhouse - this is necessary to reduce the air temperature during the day. At night, the water releases the accumulated heat, and the air temperature rises.

In no case should you turn the vines over when collecting, because then they will spend a lot of effort returning the leaves to the correct orientation relative to the sun; You need to remove cucumbers with part of the stalk, carefully cutting or breaking it off; if during harvesting part of the cucumber breaks off and remains on the bush, it must be removed so that it does not rot; You need to collect fruits every 2-3 days, not allowing them to outgrow, since the bush will waste energy on them, postponing the formation of the ovary until later.

To rejuvenate the leaves and stimulate the development of lashes, you can water and spray the bushes with a urea solution. You will need a tablespoon per 10 liters of water. How much you need to pour under each bush depends on the air temperature. The lower it is, the less feeding the plant needs.

The prevention of fungal diseases will be feeding with superphosphate, which, in addition to phosphorus, contains potassium and magnesium.

During this period, you can use whey diluted in water in a ratio of 1:3 as a fertilizer. Or add a tablespoon of superphosphate and a tablespoon of potassium sulfate to 10 liters of water.

You need to water the vegetables with warm water. It is important that the root collar remains dry.

It is important to remember that many cucumber diseases are carried by insect pests, such as aphids. Therefore, it is necessary to protect plantings from its invasion. To do this, regularly inspect the bushes, remove weeds and plant debris from the rows, spray the plants with an infusion of tobacco dust, onion peels or garlic with the addition of laundry soap. If your cucumbers are growing in a greenhouse, ventilate it regularly, maintaining a humidity level of 65-75 percent and a temperature no higher than 28 degrees.

If pests have already appeared on your cucumbers, try using biological products, such as bitoxybacillin, fitoverm, etc.

Mulch the cucumber beds with a layer of peat, sawdust or humus to protect the roots from freezing at night and from overheating in the daytime heat.

When cultivating bee-pollinated varieties, it is necessary to attract pollinating insects. To do this, plants are sprayed with a solution of water and honey (1 teaspoon per 1 liter of water). You can also attract them if you plant flowers with late flowering periods (chrysanthemums, oregano, phacelia) next to the beds.