Growing tomato seedlings for a greenhouse

Growing thermophilic tomatoes in the temperate climate of Russia is not an easy task. Tomatoes are a southern plant with a long growing season. In order for them to have time to give their harvest before the onset of the autumn cold, tomatoes need to be grown by seedlings and it is better to do this in greenhouses. This is the only way to guarantee high yields of juicy and aromatic fruits.

How to determine the time of planting tomato seedlings for a greenhouse, how to sow tomato seeds correctly and when to transfer plants to a permanent place - this is what this article is about.

Where to begin

It is necessary to start growing seedlings by choosing a variety of tomatoes. To do this, you need to prioritize and choose varieties that:

  • intended for hotbeds and greenhouses;
  • have an early or medium ripening period;
  • have the ability to self-pollinate (which is very important in a closed greenhouse);
  • resistant to fungal diseases of tomatoes, especially to late blight (the risk of developing these diseases in a greenhouse is much higher than in open ground, because there is high humidity);
  • they are distinguished by compact bushes that do not grow much to the sides;
  • indeterminate tomatoes in height should not exceed the size of the greenhouse;
  • give good yields of tasty fruits.

After choosing a variety and purchasing seeds, you can proceed to the preparatory stage. At this stage, you need to choose containers for seedlings, mix the soil or purchase a ready-made soil mixture for tomato seedlings, prepare a greenhouse for transplantation.

Determining the timing of sowing seeds for seedlings

The growing season for early and mid-season tomatoes is about 90-100 days. And the optimal temperature for tomatoes is 24-26 degrees during the day, and 16-18 degrees at night. In the local climate, such a temperature regime does not last long - a month or two. This obliges gardeners to keep tomato seedlings in the house for half or even two-thirds of the growing season or grow crops in heated greenhouses.

In the south and in the middle zone of the country, tomatoes can be planted in a greenhouse when the night frosts stop - this is about the end of April or the first days of May. In northern Russia, tomato seedlings are transferred to unheated greenhouses around mid-May or the end of the month.

In addition to the date of planting seedlings in a permanent place, it is necessary to take into account the ripening time of tomatoes. You can recognize them by examining the label of the seed bag - after all, the growing season will be different for each variety.

Based on these two parameters, the date of sowing tomato seeds for seedlings is determined. On average, this is the end of February - for the southern regions and late-ripening varieties, or early-mid-March - for the middle strip and tomatoes with early ripening periods.

Attention! When choosing a seed sowing date, be sure to take into account the climate in the region. After all, the air temperature on the same day may differ even in two neighboring cities, so the gardener must analyze the weather conditions of recent years in his particular locality.

Tomato seedlings are transferred to a permanent place only when the weather permits. Even strong and healthy plants will not be able to take root well if the light level or temperature regime does not contribute to this.

Seeding preparation

First of all, you need to stock up on containers for tomato seedlings. Any plastic containers (for example, yogurt cups), disposable plastic dishes, wooden crates, special peat cups or seedling tablets will do.

The only requirement for a seed pot is that it should not be too deep. The optimal wall height is 15 cm.

Now you need to prepare the soil for tomato seedlings. Slightly acidic soil is most suitable for this culture, the earth should be crumbly and light. You can prepare a mixture for growing tomatoes yourself, or you can use a purchased soil mixture intended for seedlings of garden crops.

Advice! In order to improve the survival rate of seedlings after transplanting, it is recommended to use the same soil that is in the greenhouse for sowing seeds. This will help the tomatoes adapt faster and get less sick.

To loosen too dense soil, you can use coarse river sand or wood ash - these components are added to the soil and mixed thoroughly.

Before use, the soil for tomato seedlings must be disinfected, this is necessary to prevent microorganisms and fungi dangerous for tomatoes from multiplying in the soil. Each gardener uses his own method for disinfection, you can choose any of them:

  1. Freezing for a long period is carried out in advance. To do this, the soil is mixed since the fall, and in the winter they keep a linen bag with soil on the street or hang it on the balcony.
  2. Calcination is carried out in an oven or in a microwave oven. For this, the prepared soil is scattered over a sheet or frying pan and heated thoroughly for half an hour. Before sowing seeds, the ground must be cooled.
  3. Boiling water is usually poured over soil that has already been poured into the boxes. The same method is suitable for disinfecting the ground in open beds or in a greenhouse - you need to water the greenhouse soil a few hours before transplanting tomato seedlings.
  4. The use of manganese is also quite effective. To implement this method, potassium permanganate is diluted in water to a dark purple liquid. This solution is poured over the ground in cups or seedling boxes.

Prepared and disinfected soil is poured into containers for growing tomato seedlings. The earth needs to be slightly moistened and tamped.

Then, with a knife or other flat object, grooves are made with a depth of about two centimeters - here in the future, tomato seeds are placed.

How to prepare tomato seeds

The timing of planting seeds for seedlings is slightly adjusted by the germination of seed material. Usually tomatoes germinate within 7-10 days, and the first pair of cotyledonous leaves develops in them approximately 20 days after sowing.

In order for the seeds to hatch faster, and the seedlings themselves to be strong and healthy, you need to thoroughly prepare the seed material for planting:

  1. You need to buy tomato seeds only from a trusted manufacturer - you should not save here. High-quality tomato seeds have already passed the stage of calibration, hardening, and disinfection. Often, elite seeds are placed in nutritional capsules to promote quicker pecking and good growth of tomato seedlings. Store purchased seeds should be no more than two years, then their germination decreases.
  2. If tomato seeds are collected with your own hands from the previous harvest, you need to remember that seeds that are two or three years old have the best germination. Therefore, you should not use last year's seeds. It is also very important that seeds are not harvested from hybrid tomatoes; only varietal tomatoes are suitable for reproduction.
  3. The material for growing seedlings is calibrated - the smoothest, most beautiful seeds of a uniform shade and the same size are selected.
  4. You can check the germination with a saline solution. To do this, dissolve a few tablespoons of salt in a half-liter jar and place tomato seeds there. After half an hour, they examine the material - only seeds that have sunk to the bottom of the can are suitable for planting. The floating seeds are hollow, nothing will grow out of them.
  5. Tomato seeds also need to be disinfected. To do this, you can use an iodine solution (1%) or a manganese solution. In this environment, the seeds are placed for 15-30 minutes, having previously tied them in a linen or gauze bag. After processing, tomato seeds are thoroughly washed with running water.
  6. You can stimulate the earliest hatching of seeds if you put them for a day or two in a thermos with water, the temperature of which is about 50 degrees. However, this step is not necessary, since many gardeners are of the opinion that tomatoes should be sown with dry seeds.
  7. If the owner, nevertheless, wants to be sure of the germination of tomato seeds, after a thermos, he can wrap them in a damp cloth and close them in a small container. It is necessary to keep the seeds in this form for two to three days, twice a day the container is opened slightly for airing.
  8. Hardening tomato seeds in the future will help the seedlings to more firmly endure low night temperatures and their fluctuations. Already germinated seeds are hardened by placing them in the zero chamber of the refrigerator for a day.
  9. You can nourish the seeds in a solution of wood ash, a couple of tablespoons of which are added to warm water.

Important! All these "operations" are performed only with home seeds, which the gardener collected with his own hands. Purchased tomato seeds have already passed all the stages of preparation, they can only be germinated in a damp cloth.

Planting seeds for seedlings

With germinated seeds, you need to be extremely careful, since delicate sprouts break very easily. Therefore, you need to germinate seeds on a cloth or cotton pad, and not on a bandage or gauze - the sprouts will easily get entangled in the fibers and break.

Transfer the seeds to the prepared grooves with tweezers. They are laid at a distance of about 2-2.5 cm from each other - this is approximately the width of two fingers of an adult hand folded together.

Now the seeds are sprinkled with dry soil and tamped a little. There is no need to water the grooves, it is better to use a spray bottle and spray water on the ground. After irrigation, the seed containers are covered with plastic wrap or transparent glass.

Place the pots and boxes in a very warm place where the temperature is constantly kept at 26-28 degrees.

After 7-10 days, the first sprouts will appear, this is a signal that the film must be removed from the boxes.

How to care for tomato seedlings

Growing tomato seedlings is a painstaking process, you need to pay attention to plants every day, because every little thing is important here.

In order for tomato seedlings to be strong, you must follow these rules:

  • after germination of the first leaves, boxes and pots with tomatoes are placed on a well-lit windowsill. If the sunlight is still not enough, the tomato seedlings will have to be illuminated with fluorescent lamps. Due to the lack of light, the plants can stretch too much, be weak and frail.
  • Until more than two leaves appear, the tomato seedlings are not watered, you can only slightly moisten the soil from the sprayer.
  • When the cotyledon leaves have formed, tomato seedlings dive into disposable containers. You need to transfer plants carefully, trying to grab a lump of soil along with the roots.
  • You can water tomato seedlings after diving. To do this, use melted or boiled water heated to 20 degrees. Cold water promotes the development of fungal diseases in tomatoes and inhibits their growth. Tomatoes should be watered at least once every 4-5 days. If the weather is sunny, the seedlings will have to be watered daily. It is important not to wet the leaves and stems, so the tomatoes are watered at the root. For this it is convenient to use a small watering can with a long spout.
  • You need to feed the tomatoes after the appearance of the cotyledon leaves, that is, after diving. For this, fertilizers are dissolved in warm water and the tomato seedlings are watered with this solution. You can use any ready-made fertilizer for flowers or seedlings, or prepare a mixture of mineral fertilizers yourself. It is not recommended to fertilize tomatoes with nitrogen solutions, this will lead to overgrowth of bushes and strong foliage.
  • Tomato leaves and stems will tell you about the lack of lighting. If the foliage turns yellow, fades, changes color or darkens at the edges, the seedlings do not have enough sunlight. The same can be said about overly stretched tomatoes - they do not have enough light, or the temperature in the room is below optimal.
  • During the day, tomatoes need a temperature in the range of 22-26 degrees, and at night it should drop to 16-18 degrees. If this regime is not observed, the seedlings will become lethargic and weak - a fertile bush is unlikely to grow from it.

How to know when seedlings are ready to be transplanted into a greenhouse

When the outside temperature stabilizes, the threat of severe frosts will pass, the seedlings need to be transplanted into the greenhouse. At this point, tomatoes must meet some requirements:

  1. The height of low-growing varieties of tomatoes should be about 15 cm; for tall tomatoes, a 30-centimeter seedling is considered the norm.
  2. By the time of transplantation to a permanent place, the stems should have at least eight true leaves.
  3. The stem diameter of sturdy seedlings should be about the size of a pencil.
  4. The bushes already have one or two ovaries with flower buds, but there are still no small fruits.
  5. Leaves are tight, bright green, without damage or spots.

Advice! If the seedlings are purchased, you do not need to choose tomatoes with too thick stems and dense leaves. Such tomatoes look presentable, but they will bear fruit badly, since they are oversaturated with nitrogen fertilizers and growth stimulants.

Tips from experienced gardeners

In the process of repeatedly growing seedlings, certain rules and skills are formed. Therefore, experienced gardeners can give some useful advice to beginners:

  • to increase yields, it is recommended to dive two plants into one pot at once. After twenty days, choose the strongest sprout and leave it, and pinch the top of the second plant. After that, the stems are tied with a nylon thread. Thus, you can get a bush with two roots, which will be twice as resistant and productive.
  • Many recommendations for growing seedlings say that before planting tomatoes in a permanent place, the soil in pots must be thoroughly moistened. However, this method leads to the breakage of part of the root system - when the glass is turned over to extract the tomato, half of the roots break off and remain on the walls and bottom of the glass. In order not to damage the roots, it is better, on the contrary, not to water the tomatoes for two or three days - the earth will shrink and move away from the walls of the glass, which will allow the plant to be removed without hindrance.
  • Since tomatoes do not tolerate transplanting well, it is better not to dive the seedlings, but immediately sow the seeds in disposable cups.
  • In the greenhouse, you need to install two horizontal bars - trellises, to which the tomatoes are tied with a soft rope or a strip of cloth. Immediately after planting, the seedlings are tied to the first trellis, which is 20-30 cm above the top of the tomato. The second support is located under the ceiling of the greenhouse, they are transferred to it when the tomatoes outgrow the lower trellis.
  • In the first weeks after planting, the seedlings are covered with spandex or lutrasil, throwing the canvas over the lower support. During the day, the greenhouse is opened for ventilation, the shelter can not be removed.

Now it became clear when it is better to plant tomatoes for seedlings for a greenhouse - to calculate the date, several factors must be taken into account at once. Planting seedlings on your own is much more effective than buying ready-made ones. After all, this is the only way to be sure of the quality of the variety, the resistance of plants and the timing of fruit ripening.

Watch the video: Growing Tomatoes Indoors With 94% Less Water And No Soil (June 2021).