How to Grow Cucumbers in a Greenhouse in Winter: Growing Tips

Fresh cucumbers are rarely found on store shelves, so experienced gardeners are starting to grow them themselves, using heated greenhouses.

However, in this matter, it is important to learn the specifics, study people's opinions and reviews, determine the timing for effective cultivation, and read useful tips.

Is it possible to grow cucumbers in a greenhouse in winter?

Growing cucumbers in a greenhouse during the winter is certainly possible. This allows you to enjoy the freshest vegetables year-round.

It is worth remembering that cucumbers need special care in a greenhouseThey are quite demanding in terms of warmth and regular watering. During the given season, cucumbers produce fruit depending on their variety. Environmental conditions will not affect the greenhouse's production as long as the proper temperature is maintained.

What should a winter greenhouse for cucumbers be like?

How to achieve good results in greenhouse design:

• ensuring a properly designed and placed greenhouse;
• availability of high-quality heating;
• humidity level regulation;
• light from additional sources;
• loosened soil.

Provide such conditions for You can grow cucumbers in a polycarbonate greenhouse or glass material in winter. Film greenhouses are not the most suitable for winter use due to their low strength: in heavy snowfall, the film can sag, and snow will accumulate on it, causing the structure to collapse.

Greenhouse design

On a one-to-two basis, the temperature outside the greenhouse has little effect on the temperature inside. When creating winter greenhouse conditions, gardeners often use polycarbonate and glass. And if the greenhouse is located in the southern part of the country, where temperature fluctuations are low, it's possible to use thick polyethylene film.

The primary requirement is to protect the crop from cold and allow maximum sunlight penetration. The greenhouse roof is often glass or polycarbonate, and the frame is made of wood or metal. The slope of the south-facing wall in this type of greenhouse depends on the sun's angle above the local horizon. Optimal sunlight penetration at midday is considered to be at a 90-degree angle through the glass.

The beds in the greenhouse should be sloped or stepped. This allows the sun to freely illuminate the plants and warm them well. Paint the back wall of the greenhouse white or cover it with foil, as the sun will reflect off it and illuminate the plants from behind.

The greenhouse will be easily accessible through a vestibule. This will protect the cucumbers from the cold. A water tank and heating system can be installed there. Ventilation in the winter greenhouse should not be provided through a window, as cucumbers do not need drafts. The best option is a supply and exhaust system using plastic pipes.

Heating

Cucumbers don't thrive in excessively dry conditions, so heating devices should be avoided in greenhouses, as they dry out the air. The best solution is a water-based heating system: the soil is heated by pipes and the air is heated by radiators.

A dedicated boiler or stove can be used to heat the coolant. The former is more suitable due to its superior combustion efficiency and automation. The boiler can be gas, electric, or solid fuel-fired. Power should be calculated using the formula: one kilowatt per approximately ten square meters.

Greenhouse lighting

During winter, cucumbers require additional lighting. Supplemental lighting can be easily achieved by using special lamps. However, it's important to consider several parameters, namely the level of illumination and color temperature.

Plants require daylight or as close to it as possible. This lighting should have a color temperature of 5,000 Kelvin. Fluorescent, mercury vapor, and metal halide lamps are good sources. During the growth stage, it's best to use lamps with a cooler color temperature (approximately 6,500 Kelvin), while during flowering and fruiting, use lamps with a warmer color temperature (approximately 4,000 Kelvin). Under these conditions, plants will remain strong and produce good fruit.

Special LED grow lights are also suitable for lighting. LEDs have a red-blue spectrum, which accelerates growth and improves fruiting. Long-term exposure to this spectrum is extremely harmful to human vision, so greenhouse work should be done in natural light.

Soil work

Soil preparation should be completed in time to sow in late September and harvest by early January. The next sowing can be done at the end of the first month of winter. If the greenhouse is new, it's necessary to prepare a mixture rich in organic matter, disinfect the soil, fertilize it, and dig it to a depth of approximately thirty centimeters.

Replacement and disinfection of soil

If the greenhouse is no longer new, the gardener should remove the top layer of soil and replace it (about fifteen centimeters). The mixture can consist of humus and forest soil (mixed in a one-to-one ratio). In peat-rich areas, high-moor peat is used as a base, to which garden soil, untreated with herbicides and other chemicals, and humus are added in a 50:20:30 ratio. The mixture should be thoroughly turned and packed into the beds.

The next step in preparation is soil disinfection. The most optimal method involves watering the substrate with a copper sulfate solution (concentration: five to seven percent).

Application of fertilizers and special substances

The soil should be fertilized with mineral-based fertilizers, such as Kemira or Nitrophoska. Dig the soil to a depth of thirty centimeters. The soil temperature should be approximately twenty degrees above zero at the time of sowing. About a week before sowing, to enrich the soil with beneficial microflora and eliminate harmful elements, add a solution of "Ecomik Urozhainy" or "Baikal EM-1" at a ratio of one hundred milliliters of the substance per liter of water. Sow the seeds in late October or plant the seedlings in the last ten days of October.

Varieties of cucumbers for winter cultivation

Hybrids are the best choice, as they don't require pollinators and thrive in low light conditions. The table below shows the most popular winter cucumber varieties:

Seed preparation

The seeds must be sorted, removing any damaged or bad ones. Next, place them in salted water, discard any that float to the surface, and rinse them to remove the salt. Gardeners choose their own disinfectant solution, strictly on a case-by-case basis. Diluted boric acid or potassium permanganate works well for disinfecting seeds. Treated seeds can be stored in the refrigerator for about a week, placed on regularly moistened cheesecloth, and then used for planting.

Technology for growing cucumber seedlings in a greenhouse in winter

Seeds should be sown in peat pots or specialized "tablets." Seedlings should be planted without disturbing the root ball. If transplanting seedlings from different containers, leave the root collar above the soil surface to reduce the risk of infection. Plants 25-30 days old with 3-4 leaves should be planted in the ground.

Agricultural technology for growing cucumbers in a winter greenhouse

In a greenhouse, cucumbers are best grown using seedlings, as this method promotes strong plants and reduces harvest time. If a gardener uses store-bought seeds, they don't need to perform any pre-planting preparation.

Sowing seeds and planting seedlings

The frequency of sowing seeds or seedlings depends directly on the cucumber variety and is approximately two to four plants per square meter, ensuring sufficient space for growth and good light distribution. When planting in rows, leave approximately forty-five centimeters between seedlings. After planting, install wire trellises and tie them to twine or specialized netting.

Temperature conditions

Throughout the cucumber growth period, the soil temperature should be between 15 and 18°C. Lower temperatures can increase root fungal infection. Daytime temperatures should range from 23 to 25°C, and nighttime temperatures should range from 18 to 20°C.

Watering and air humidity

Cucumbers prefer a moist environment and require regular watering. Fluctuations in soil moisture are unacceptable. From planting until flowering, water moderately to prevent the plant from developing a large leaf surface. Watering should be done approximately every five days. Once flowering begins, increase watering to three times every seven days.

During fruiting, the watering rate should be increased to ten liters per square meter. Plants should be watered with warm, settled water, close to the soil temperature (approximately twenty degrees Celsius).

If the roots are exposed, it's worth hilling the plant or adding potting mix. It's best to water the plants in the morning or evening to avoid burning them during the high solstice. When the temperature reaches 25 degrees Celsius, ventilate the greenhouse, but avoid drafts.

Top dressing

For example, you can use chicken manure as fertilizer (in a ratio of one part to fifteen). To enrich the infusion with microelements, add wood ash (one cup per bucket). Stir and let it steep for 2-3 days.

For prevention, spray the plants with Fitosporin three times every fifteen days, which prevents the appearance of fungus.

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Post-transplant care

Cucumbers need to be fed once every fourteen days, alternating between mineral-based and organic fertilizers. Maintaining high humidity is also crucial. To ensure this, the floor and heating pipes should be constantly watered. Open reservoirs should be placed inside the greenhouse to provide air humidification, settling, and heating of the water.

Before flowering, plants need to be watered twice every seven days, and then more thoroughly and more frequently. Keep the leaves firm and succulent. Wilted, dry leaves indicate extreme water stress. Young plants should be illuminated with low-hanging lamps, and then the lamps should be raised as the plants grow. Daytime temperatures should be above 20°C (78°F). Ventilate the greenhouse carefully, preventing cold air from penetrating directly onto the shrubs.

Tips from experienced gardeners

It's important to distribute the space as best as possible to avoid any inconvenience when caring for the plants. First, thoroughly dig and loosen the soil, then determine the number of beds:

1. You can place one large bed in the center of the greenhouse, then the plants will be accessible from all sides.
2. You can separate two beds with paths in the center, on the sides or across, which will greatly simplify maintenance.
3. There is also the option of creating two wide side beds with one path in the center, which will make it convenient to care for the plants and will distribute the space efficiently.

Gardeners typically use wooden beams to mark out the garden beds. The width of the path is at least sixty centimeters.

Reviews

Anna Mikhailova, 35 years old

You can always grow cucumbers, given the availability of special "winter" varieties for greenhouses. And be sure to avoid drafts! Yes, you'll need to provide ample lighting in winter, as natural light won't be enough for fruit set. And don't forget about fertilizing seedlings and mature cucumbers; I recommend "Baikal."

Kirill Matveev, 56 years old

I grew cucumbers using a similar method. I can say that this requires LED lamps with a specific range of light levels. Super-warm white is 2,700 Kelvin, warm white is 3,000 Kelvin, natural white is 4,000 Kelvin, and cool white is over 5,000 Kelvin. This is because the full spectrum of light is needed. Standard LED lamps are not suitable for this purpose. It's also important to maintain the correct lighting conditions both inside the greenhouse and in the soil to prevent the ground from freezing.

Conclusion

It's worth noting that to extend the fruiting period of cucumbers in winter, they need to be planted in stages, constantly replanting. By properly applying theoretical knowledge, modern techniques, and equipment, a gardener can reap a very rewarding harvest.