Growing a record harvest of tomatoes in a polycarbonate greenhouse: planting and care, advice from agronomists

Greenhouses with polycarbonate coating are confidently replacing their film and even glass predecessors. Their growing popularity is explained not only by ease of installation and relative cheapness, but also by the properties of polycarbonate.

Inside such a greenhouse a special microclimate is created for plants. Since planting crops can be started much earlier than the beginning of the season and finished much later, the fruiting period is extended and the yield increases. In this article we will look at how to grow a rich harvest of tomatoes in a greenhouse.

The best varieties for the greenhouse

To grow a good harvest, agronomists advise purchasing F1 varieties or hybrids that are disease-resistant. The best option for polycarbonate greenhouses is indeterminate varieties, which are characterized by unlimited growth.

The following hybrids are well suited for growing in polycarbonate greenhouses: Alexia F1, Ivanhoe F1, Michelle F1, Imperia Raspberry F1, Catherine the Great F1, Evpator F1, etc. Caring for them is simple, but requires the formation of a bush into one trunk, constant pinching, and feeding throughout the season. Some of the varieties can be grown in winter in heated greenhouses.

Varietal tomatoes, such as Honey Drop, Thick Cheeks, Slivka Moskovskaya, Di Barao group of varieties, are also successfully grown in polycarbonate greenhouses. Bull's heart, Heart of Gold and others.

How to choose tomato varieties for a polycarbonate greenhouse?

The choice of variety for growing in a greenhouse depends on the purpose of cultivation (for juice, salad, whole-fruit canning, for drying), as well as on specific conditions (climate, area and heating of the greenhouse, etc.).

Keep in mind that for cold regions, early or mid-season varieties or hybrids are suitable, which, when sown as seedlings in early March in a polycarbonate greenhouse, have time to ripen.

How to grow strong tomato seedlings?

The key to a rich harvest is healthy and strong seedlings. Properly grown seedlings quickly take root in the soil, form a strong green plant, begin to bloom and bear fruit within the time limits established for this variety.

To grow it correctly, you need to know some of the subtleties of preparing soil and seeds for planting, as well as the features of caring for seedlings.

When to plant tomatoes as seedlings for a greenhouse

With a greenhouse, summer is extended by about four weeks, and if you have a heated greenhouse with lighting, then it will last all year round.

Not all gardeners can afford heated polycarbonate greenhouses, so most plant tomatoes in unheated greenhouses. For this reason, we give the timing of planting tomatoes for seedlings for unheated greenhouses.

Residents of the middle zone are recommended to plant tomatoes in the first half of March. It is better for gardeners in the northern regions to start planting in early April. At the time of planting in the greenhouse, seedlings should be 30-40 cm high, with 9-10 leaves.

How to prepare a greenhouse for planting tomatoes

Preparing the greenhouse for spring planting begins in the fall. Remains of plants, weeds, supports and garters are removed from the greenhouse. Tops affected by diseases and pests are burned.Healthy plants and weeds can be placed in a compost heap, layered with organic fertilizers or spilled with a urea solution.

The greenhouse should be washed with a sponge soaked in soapy water or a detergent solution. Another option is to use a sponge mop on the handle - this will make the job easier. First, apply a soap solution, let it “work” for 5-10 minutes and rinse off with clean water from a hose.

Attention! It is forbidden to use aldehydes, chlorine, solvents, or abrasive substances as a cleaning solution, since the top layer of polycarbonate does not tolerate aggressive influence. When using them, scratches and stains may remain on the surface.

The next important step is treatment and disinfection of the greenhouse. First, decide on the scale of the work. If there were practically no pests or diseases in the greenhouse over the summer, it is enough to treat with gentle biological products (“Fitosporin”, “Glyokladin”, “Trichotsin”, “Baikal-EM1”; “Shine”; “Phoenix”; “Fitop-Flora-S” " and so on.).

Advice. Since fungal spores and bacteria are found primarily on the surface of the soil, it should not be dug up before treating with antibacterial compounds and fungicides.

Simultaneously with the application of biological products, complex fertilizers are applied to the soil: superphosphate, nitroammophosphate or organic matter.

Use chemicals if plant diseases or a large number of pests have been reported in your greenhouse or in your neighbors over the summer. Excellent results are obtained by copper sulfate, pharmacoid, bleach, Bordeaux mixture, formaldehyde, and freezing.

A radical method of combating pests and bacteria is a sulfur bomb. It is effectively used to combat whitefly.The smoke emitted by a sulfur bomb contains sulfur dioxide, which kills parasites, pests and microorganisms.

Attention! A coating may appear on the walls of the greenhouse and the frame, which is better to carefully wash off with a sponge, being careful not to let it get on the soil. Upon contact with water, it turns into acid and acidifies the soil.

A much simpler and “cleaner” radical method of combating whiteflies and other types of insects, pests and diseases that hibernate in the soil is to freeze out the greenhouse. To do this, open the windows or doors slightly.

In addition, an open window helps to equalize the temperature inside the greenhouse, as a result of which condensation and ice will not form on its walls, and it will be much easier to remove snow from the polycarbonate.

In winter, the main concern of a good gardener is to prevent snow and ice from accumulating on the roof of the greenhouse. They can damage polycarbonate. To reduce problems with snow removal, we recommend choosing greenhouses with a steep roof slope or a streamlined shape.

If the roof of the building is flat or arched, then it must be regularly cleared of snow masses.

Planting seedlings and caring for tomatoes

To keep tomato seedlings healthy and strong at home, you need to:

• select and/or prepare the soil correctly;
• select varieties;
• prepare seeds;
• sow on time;
• maintain water balance;
• carry out fertilizing;
• dive correctly.

Soil preparation

The stores offer a large selection of soil mixtures for growing seedlings. We advise you to choose such proven brands as “Living Earth”, “Microgreenhouse”, Biud Soil”, “Gumimax”, “Garden Earth”.

If you don’t trust store-bought soil, prepare it yourself from equal parts peat and sand with the addition of sawdust or mullein.

Be sure to disinfect the soil before planting - it doesn’t matter whether it’s store-bought or prepared yourself. To do this, the soil is placed in special containers and placed in a microwave or oven for 20-30 minutes. Then the soil mixture is spilled with a solution of phytosporin, and the soil temperature should not be higher than 25-30°C.

Seed preparation

Before sowing, the seeds must be sorted, leaving large and full ones. Selected seeds for the prevention of viral diseases are kept in a weak solution of “Imunocytophyte” (1 tablet per 100 ml of water) for 3-12 hours.

An alternative is to hold Fitosporin in the solution.

A solution of potassium permanganate (potassium permanganate) works well. The seeds are soaked in a 1% solution of potassium permanganate for 45 minutes. After this, the planting material is rinsed with water and dried.

Timing for planting seeds for seedlings

Don't rush to sow early, in January or February. With such sowing, seedlings turn out to be “tortured”, take root less well and produce a harvest later. In the conditions of Central Russia, it is better to sow seeds for seedlings in March.

Sowing seeds

Prepared seeds are sown in small boxes or containers about 15-20 cm high, with a distance between seeds of 5-10 cm. The seeding depth is 1 cm. If you do not want to pick up the seedlings, it is better to plant the seeds not in boxes, but each in a separate cup or peat pot.

Plant the seeds in moist soil warmed to room temperature. Until the first shoots appear, containers with seeds should be under film or glass.

After germination, the film or glass is removed and the container is transferred to a lighted windowsill. It is enough to water young seedlings twice a week using a fine spray.

Picking seedlings

After 2-3 true leaves appear (approximately 2-3 weeks after sowing), the seedlings are pruned.

Picking seedlings is a serious stress. Therefore, after this procedure, the seedlings need special care, which means that they should not be in direct sunlight, the room should not be hot - preferably the temperature should be about +18°C.

During the rooting period (3-5 days), we water the seedlings especially carefully. Plants respond well to feeding with preparations such as Zircon and Atlet.

Transplanting plants into a greenhouse

Proper planting and care are the key to a good harvest. One of the main conditions for success is the successful choice of planting dates if the greenhouse is unheated. Sudden temperature changes are stressful for young plants.

In the middle zone, tomatoes begin to be planted when the ground has warmed to a depth below 20 cm, i.e. from the end to the middle of the first ten days of May. It is recommended to transplant into a greenhouse when the length of the plant stem reaches 30-40 cm, and the number of true leaves is 9-10 pieces.

In the northern regions, choose tomato varieties with a shorter life cycle than for the middle zone.

Planting schemes

A well-chosen planting scheme should provide the plants with good lighting. The distances between seedlings depend on the tallness of the plants and growing conditions.

So, when growing tall tomatoes, the distance between rows can reach up to 1 m, between bushes - 70 cm.In some cases, the interval can be reduced: 70-90 cm between rows and 50-60 cm between bushes.

The distances between bushes of medium-sized tomatoes can be reduced to 55 cm, and between rows to 70-80 cm. It is permissible to slightly change these parameters taking into account the variety.

Plant arrangement

It is best to “stretch” the beds along the long walls of the greenhouse and arrange them in the form of two or three separate strips or in the form of the letters “P” or “W”, with their legs facing the entrance.

The width of the beds is calculated individually, its optimal value is 60-90 cm. The main thing to remember is that the minimum distance between bushes when planting cannot be less than 50 cm, and you need to retreat 10 cm or a little more from the border of the bed.

Reference. Greenhouse beds are usually made 20-40 cm above the ground level, because soil raised above the ground warms up better and faster.

Caring for seedlings in a greenhouse

The seedlings will take root in the first 10-15 days after planting in the greenhouse. For this process to be successful, it is necessary to maintain the temperature in the range of 20-22 °C and shade the young plants from direct sunlight.

Watering the seedlings begins after 10 days, since at the time of transplantation the plants are well watered. To get a decent harvest of tomatoes in a greenhouse, you need high-quality care of the crop throughout the summer: pruning, watering and fertilizing in a timely manner.

How to care for tomatoes in a greenhouse

Seedlings planted in a permanent place need proper care, without which it will be difficult for them to take root and gain strength. Caring for plants after planting in a greenhouse will not cause difficulties if you follow the basic rules:

1. The first watering is carried out after planting tomatoes in the ground.. It should be plentiful and wet the soil by 15-20 cm to ensure good contact of the roots with the soil.
2. Ventilation. It is necessary to open the doors and all existing windows after watering so that condensation does not form on the polycarbonate walls and roof and the humidity does not rise to unacceptable limits.
3. Start watering no earlier than the seedlings begin to grow. Stretching of the stem and branches is a signal that the plant has taken root and needs food, including water. It is not recommended to water earlier, since excessive moisture can lead to rotting of the roots and death of the seedling.

Water consumption for young plants is 5-7 liters per 1 m² of bed. As the bushes develop, the norm increases: with the beginning of flowering up to 12 liters, and with the onset of hot weather and the beginning of fruiting - up to 15 liters.

It is recommended to water in the absence of direct sunlight - in the evening or early morning. The soil moisture level should not exceed 70%.

Garter and feeding

Mandatory event when growing tomatoes - garter. Tied bushes are better illuminated and ventilated than those spread on the ground. In addition, tying the bushes to a support reduces the risk of the spread of fungal diseases.

Tomatoes are fed 3-4 more times during the season. In the initial period of development, it is best to use mullein or a fermented aqueous solution of cow manure for tomatoes. Also, ammonium nitrate and urea are used as the first feeding at the rate of 1 tbsp. spoon on a bucket of water.

Advice. Any fertilizer applied to tomatoes is carried out only after watering.

Feeding during flowering

During the period of budding and flowering of the first two clusters, the watering rate of tomatoes is reduced to 1-2 liters per bush, with an interval between waterings of 5-7 days. They do this to inhibit the growth of green mass and stimulate the formation of ovaries.

During the flowering phase, it is necessary to feed tomatoes with fertilizers containing potassium and phosphorus. The main emphasis is on foliar feeding, since in this case the necessary elements are absorbed by the plants faster.

Superphosphate (2 tablespoons per 10 liters of water), potassium monophosphate (2 tablespoons per 10 liters of water), as well as complex fertilizers (“Solution”, “Master-agro for tomatoes” and others) are used as fertilizers.

Good results are obtained by feeding with a milk solution with iodine (1 liter of milk, 15 drops of iodine, 10 liters of water), yeast feeding (10 g of yeast, 2 tablespoons of sugar, a bucket of water).

Foliar feeding of tomatoes is carried out every 7-10 days. To stimulate the formation of ovaries during flowering, tomatoes are treated boric acid solution, for the preparation of which 5 g of the drug is dissolved in 10 liters of water, or sprayed with the drug “Ovary”.

There is an opinion among experienced gardeners that during the growing season of tomatoes it is necessary to carry out at least three foliar feedings in the following phases of plant development:

• in the phase of two true leaves of tomato seedlings;
• during flowering;
• during the period of mass fruiting in the second half of summer.

However, the use of foliar feeding on tomatoes is not limited in any way; they can be performed every 10 days during the entire growing season, alternating with root feeding.

Watering and fertilizing during fruit ripening

When the tomatoes begin to ripen, watering is increased more often, preventing the soil under the plants from drying out.To better retain moisture in the soil, plantings are mulched with straw, compost, and humus. In extreme heat, peat or sawdust is poured around the trunks.

Advice! When watering, follow the rule: if the soil is dry at a depth of 2-3 cm, then it’s time to water the tomatoes, and if it’s still wet, you can hold off on watering.

On a hot sunny day, tomatoes are watered either early in the morning or two hours before sunset. After each watering, it is advisable to loosen the soil around the tomatoes, avoiding the formation of a crust on the soil.

During the ripening phase of tomatoes, potassium and phosphorus fertilizers are applied every two weeks.

Important. You can feed tomatoes with ash solution only after preliminary watering, otherwise the roots will get burned.

During the ripening period, you should not fertilize plants with nitrogen-containing fertilizers, including organic ones (mullein, chicken droppings, etc.).

Possible pests and diseases

To protect tomatoes from pests and diseases, it is necessary to periodically carefully inspect them and carry out preventive treatment.

The most common pests of tomatoes: spider mites, whiteflies, cutworms, root-knot nematodes, wireworms, mole crickets.

From insect pests Spraying with Fitoverma solution helps a lot. In addition to them, pathogens of various diseases can also enter indoor soil.

Diseases of tomatoes in a greenhouse are divided into three groups:

• fungal diseases (powdery mildew, gray rot, late blight, cladospora blight, alternaria blight, anthracnose, fusarium blight, root rot, sclerotinia blight, didimella fungus);
• viral diseases (aspermia, necrosis, mosaic);
• bacterial (black spot, tomato cancer).

The best way to deal with them is prevention. First of all, seeds and soil are disinfected. After transplanting plants into the greenhouse, carry out regular ventilation, and when condensation appears on the walls, wipe them dry.

Watering should be adjusted so that there is no stagnation of moisture. The soil around the plants is mulched with hay, sawdust, etc. Diseased plants are removed and burned, tools are disinfected.

Attention! The use of chemicals should be stopped two weeks before harvest. For herbal preparations this period is 5 days. The exception among them is chamomile. Preparations based on it can be used at any time.

Stepsoning

Growing tomatoes in a polycarbonate greenhouse will not bring the expected result if pinching and bush formation are not carried out in a timely manner. Tall varieties of tomatoes form a single stem.

Medium and low-growing tomatoes in the greenhouse are formed into two or three stems. To do this, a reserve shoot is left above the first flower cluster, which will continue to grow after the growth of the main stem stops. The third shoot is left above the second brush. All shoots located above the second brush are removed.

Temperature conditions in the greenhouse and ventilation

Tomatoes are grown in a temperature range of + 20-22 °C, while during the day an increase to +25 °C is acceptable, but +28 °C is already a threshold, exceeding which can lead to the falling of leaves, flowers or ovaries. Maintain the night temperature in the range of +16-18 °C, but not lower than +15 °C. Therefore, it is important to ventilate the greenhouse.

Proper ventilation of the greenhouse stabilizes the temperature and humidity of the air. For good ventilation, you will need wide transoms with a total area of ​​at least a quarter of the greenhouse area, and preferably along the top of the structure, where hot air accumulates.To reduce the temperature in it, it can be slightly shaded during peak solar activity.

Harvest and storage

Harvest time depends entirely on the air temperature and humidity in the greenhouse. This period also depends on the plant variety.

The health and maturity of the fruit depends on the correct timing, which will affect not only the taste characteristics of the tomatoes, but also their transportability and shelf life.

When picking tomatoes, adhere to the following rules:

1. The fruits should be slightly unripe, with a light brown color and green spots.
2. Collect the fruits together with the stalk. This will keep the tomatoes firm and full of vitamins and other useful components.
3. Harvest tomatoes before night temperatures drop below 8˚C.

Some tips for proper care of tomatoes

The success of growing tomatoes in a polycarbonate greenhouse depends on many factors:

• varieties;
• seed health;
• temperature regime (25-28°C during the day, and not lower than 15°C at night);
• soil temperature (not lower than 17-18°C);
• air and soil humidity in the greenhouse (not higher than 65%);
• correctness of stepsoning;

When growing tomatoes, you need to remember some “don’ts”:

• Plants should not be grown in oily soil that is overly fertilized with organic matter;
• Bird droppings and manure should not be placed in holes for tomatoes, as they will cause the plants to turn into greens and not into fruits;
• You cannot fertilize tomatoes with mullein more than three times a season;
• You can’t put urea under the plants, you can only spray it once at the beginning of the growing season;
• Plants should not be planted in the shade or too densely;
• Do not overfill tomatoes with water.

After the second half of July, feeding tomatoes should be stopped.

What is the difference between the process of growing tomatoes in a greenhouse?

Growing tomatoes in a polycarbonate greenhouse is significantly different from the same process in open ground conditions.

In a polycarbonate greenhouse, the temperature on hot sunny days can rise above +50-55 degrees. Therefore, when choosing a greenhouse design, you should consider the ventilation system. It is better that the greenhouse is equipped with a system of vents in the roof.

Humidity in a greenhouse is higher than in open ground. Permissible air humidity is 60%. At higher rates, ventilation is carried out, otherwise the risk of fungal diseases increases, and the fruits may crack.

Another feature of the greenhouse is the absence of pollinating insects and wind. Although tomatoes are a self-pollinating crop, in closed soil conditions the pollen needs to be helped to get to the pistil. To do this, shake the flower brushes slightly.

Conclusion

Growing tomatoes in a polycarbonate greenhouse is quite simple, but you need to know the characteristics of the growth and development of tomatoes in closed ground. Remember that compliance with agrotechnical standards will ensure good yields and help prevent diseases.