Growing tomato seedlings for a greenhouse

Growing heat-loving tomatoes in the temperate climate of Our Country is not an easy task. Tomatoes are a southern plant with a long growing season. In order for them to have time to give up their harvest before the onset of autumn cold weather, 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 fragrant fruits.

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

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:

• designed for greenhouses and greenhouses;
• have early or medium ripening;
• 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 the open field, because there is high humidity);
• differ in compact bushes, not very growing 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 buying seeds, you can proceed to the preparatory stage. At this stage, you need to choose containers for seedlings, mix the soil or purchase ready-made soil mixture for seedlings of tomatoes, prepare a greenhouse for transplanting.

Determining the timing of sowing seeds for seedlings

The growing season for early and mid-ripening 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 half or even two-thirds of the growing season to keep seedlings of tomatoes in the house 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 around the end of April or the first days of May. In the northern part of Our Country, tomato seedlings are transferred to unheated greenhouses around mid-May or at 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 timing of the ripening of tomatoes. You can recognize them by examining the label of a bag of seeds – 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 the beginning-mid-March – for the middle lane and tomatoes with early ripening.

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 this is not facilitated by the level of illumination or temperature.

Preparing for seeding

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

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

Now you need to prepare the soil for seedlings of tomatoes. This culture is most suitable for slightly acidic soil, 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.

It is possible to loosen too dense earth with the help of coarse-grained river sand or wood ash – these components are added to the soil and mixed thoroughly.

Before using the soil for tomato seedlings, it is necessary to disinfect it, this is necessary in order to prevent the reproduction of microorganisms and fungi dangerous for tomatoes 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 autumn, and in winter they keep a linen bag with soil on the street or hang it on the balcony.
2. The calcination is carried out in an oven or in a microwave oven. To do this, the prepared soil is scattered over a sheet or pan and warmed up well for half an hour. Before sowing seeds, the ground must be cooled.
3. They usually pour boiling water over the soil, which is already poured into the boxes. The same method is suitable for disinfecting the land 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 the state of a dark purple liquid. This solution is poured over the ground in cups or boxes for seedlings.

Then, grooves about two centimeters deep are made with a knife or other flat object – tomato seeds are subsequently placed here.

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 cotyledon leaves develop 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 properly 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, disinfection. Often, elite seeds are placed in nutrient capsules that help to accelerate spitting 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 to 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 collected from hybrid tomatoes; only varietal tomatoes are suitable for propagation.

   

3. The material for growing seedlings is calibrated – the most even, 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 inspect the material – only seeds that have sunk to the bottom of the can are suitable for planting. Floated seeds are hollow, nothing will grow from them.
5. Tomato seeds also need to be disinfected. To do this, you can use a solution of iodine (1%) or a solution of manganese. In this environment, the seeds are placed for 15-30 minutes, after tying them in a linen or gauze bag. After processing, the tomato seeds are thoroughly washed with running water.
6. You can stimulate the early spitting of seeds if you place them for a day or two in a thermos with water, the temperature of which is about 50 degrees. However, this stage is optional, 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, he can wrap them in a damp cloth after a thermos 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 slightly opened for ventilation.
8. Hardening the seeds of tomatoes in the future will help the seedlings to more endure low night temperatures and their fluctuations. Already sprouted seeds are hardened by placing them for a day in the zero chamber of the refrigerator.
9. You can feed the seeds in a solution of wood ash, a couple of tablespoons of which are added to warm water.

Planting seeds for seedlings

With germinated seeds, extreme care must be taken, as tender sprouts break very easily. Therefore, you need to germinate the 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 into the prepared grooves using 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. It is not necessary to water the grooves, it is better to use a spray gun and spray water on the ground. After irrigation, seed containers are covered with plastic wrap or transparent glass.

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

How to care for tomato seedlings

Growing tomato seedlings is a painstaking process, attention to plants must be paid daily, because every little thing is important here.

In order for tomato seedlings to be strong, the following rules must be followed:

• after the germination of the first leaves, boxes and pots of tomatoes are placed on a well-lit windowsill. If there is still not enough sunlight, tomato seedlings will have to be illuminated with fluorescent lamps. Due to the lack of light, the plants may 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. Plants should be transferred carefully, trying to grab a lump of soil along with the roots.
• Tomato seedlings can be watered after diving. To do this, use melted or boiled water heated to 20 degrees. Cold water contributes to the development of fungal diseases of tomatoes and inhibits their growth. Tomatoes should be watered at least once every 4-5 days. If the weather is sunny, the seedlings will need to be watered daily. It is important not to wet the leaves and stems, so the tomatoes are watered under the root. To do this, it is convenient to use a small watering can with a long spout.

  

• Tomatoes need to be fed after the appearance of cotyledon leaves, that is, after diving. For this, fertilizers are dissolved in warm water and seedlings of tomatoes 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 excessive growth of bushes and strong foliage.
• Leaves and stems of tomatoes will tell 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 – it is unlikely that a fertile bush will grow out of it.

How to know that the seedlings are ready for transplanting into the greenhouse

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

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

Tips from seasoned gardeners

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

• to increase productivity, it is recommended to dive into one pot at once two plants. After twenty days, the strongest sprout is chosen and left, and the top is pinched to 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 ground in pots must be thoroughly moistened. However, this method leads to the breakage of part of the root system – when the cup 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 easily removed.

  

• 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 crossbars – trellises, to which the tomatoes are tied with a soft rope or strip of cloth. Immediately after planting, the seedlings are tied up on 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 switch 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 has become 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 yourself 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, plant resistance and the timing of fruit ripening.