At what temperature to plant tomatoes in the ground

To the question: "At what temperature can tomatoes be planted?" even the most experienced gardener cannot give an unambiguous answer. The thing is that tomato is a capricious and very thermophilic culture. To calculate the timing of planting a tomato, you need to take into account a number of factors. And still, it is unlikely that it will be possible to achieve an excellent result from the very first time, because growing tomatoes is a process divided into several separate stages, each of which requires adjusting all modes, including temperature.

When it is necessary to plant tomatoes, and what these terms depend on - let's try to figure it out in this article.

Temperature groups of tomato

Like any crop, tomatoes have their own growing season, which is directly related to the vegetable variety. That is why, first of all, the gardener should familiarize himself with the recommendations of the tomato seed manufacturer, you can find this information on the seed bag.

Of course, the manufacturer's instructions are very approximate, but thanks to them, you can understand to which temperature group a particular tomato variety belongs. And there are only three such groups:

  1. The first category includes the most cold-tolerant tomato varieties, which, as a rule, are tomatoes with an early ripening period. These crops are zoned for the climate of the northern regions, but they can be used in the middle lane and in the south of Russia, if the seedlings of such tomatoes are planted earlier. So, the first group of tomato seedlings is planted in a permanent place when the night temperature does not drop below 11 degrees, and the heat is maintained at 15 degrees during the day. This planting method is good because the root system of the tomato can get the maximum amount of moisture remaining in the ground after winter. In time, this period falls approximately at the end of April - the first days of May.
  2. The timing of planting tomato seedlings belonging to the second temperature group coincides with about mid-May. By this time, the night temperature in the region should be at the level of 14-15 degrees, while during the day it is recommended to warm at least 15-20 degrees. The largest part of tomato seedlings is planted during this period, since it is considered the most favorable: tomatoes are no longer threatened with frost, and there is still enough moisture in the ground for the development of the root system.
  3. Tomato seedlings planted in the ground after the thermometer has stabilized at 20 degrees belongs to the third temperature group. Not all tomato varieties are able to develop normally in such conditions, because the roots no longer have enough moisture, and the sun is too hot for the tender leaves of young seedlings. In addition, late planting threatens tomatoes with various diseases and fungal infections. However, it is this method that is suitable for the latest tomato varieties. And in the northern part of the country, gardeners do not plant tomatoes on the garden before the end of May or even the beginning of June.

Important! All tomato seedlings must be divided into several groups and planted at intervals of 7-10 days.

This significantly increases the chances of getting a good harvest, moreover, such a scheme will help determine the most favorable planting dates for a particular tomato variety in a particular region.

The dependence of the timing of planting tomatoes on the rate of ripening

Everyone knows that tomatoes are early, mid and late. Such varieties have characteristic features and, of course, differ in the length of the growing season. The temperature required by tomatoes for normal development can also differ depending on the speed of their ripening.

The following dependence is observed here:

  • Late-ripening tomatoes and indeterminate (tall) tomato hybrids are sown on seedlings from 15 to 25 February. By the time the plants are transplanted, the seedlings should be about 70-80 days old, so the timing of planting them in a greenhouse or in open ground corresponds to the first decade of May.
  • Tomato varieties with medium duration ripening and the same hybrids must be sown on seedlings on March 5-10, and transferred to a permanent place somewhere on May 10-20.
  • Early maturing seeds, as a rule, they are sown from March 15 to 25, seedlings can be taken out under cover in mid-May, and in open ground - not earlier than the first days of June.

Attention! And yet, a lot depends on in which part of the country the region with the garden plot is located, because the climate and average temperature directly depend on this.

These indicators are the main ones when calculating the timing of planting tomatoes.

At what temperature to plant tomatoes

The process of growing tomatoes is divided into several stages:

  • preparing tomato seeds for planting;
  • planting seeds for seedlings;
  • diving tomato seedlings;
  • hardening tomatoes before planting in a permanent place;
  • planting seedlings in open ground or in a greenhouse.

But even after all these stages, the temperature of the air and soil can significantly affect the development of tomatoes and their yield. Moreover negative can be the impact of both too low and excessively high thermometer readings.

Important! Most tomato varieties respond to such critical temperatures: 5 degrees at night and 43 degrees during the day.

It is under such conditions that irreversible processes begin in plants leading to the rapid death of tomatoes.

Not only critical thermometer marks negatively affect tomatoes. For instance, prolonged coolness at 16 degrees during the day will result in the following:

  • stopping the growth of lateral shoots on the tomato root system;
  • the inability to absorb mineral substances and moisture by the roots;
  • a decrease in the number of ovaries and a decrease in tomato yield.

Constant heat in the range of 30-33 degrees also ends badly - tomatoes shed their leaves and flowers, which leads to zero yields.

The fight against the cold is aimed at sheltering the plants, so tomatoes are often grown in greenhouses, temporary greenhouses, and the seedlings are covered overnight with agrofibre or plastic wrap. It is also possible to prevent overheating of plants: tomatoes are shaded, the ground around the bushes is mulched to reduce the evaporation of moisture from the soil, the bushes are often watered.

Seed preparation and planting tomato seedlings

To plant seedlings, you need to purchase or collect yourself high-quality planting material - tomato seeds. Before planting, the seeds are prepared in a certain way, one of the preparation stages is the hardening of the planting material: first, the seeds are heated, then placed in the refrigerator for several days.

Proper preparation contributes to the readiness of seeds for harsh climatic conditions, seedlings obtained in this way will be able to withstand temperature drops and jumps, and better acclimatize in a new place.

After the seeds have been sown, the containers are covered with foil and placed in a warm place - tomatoes can germinate only when the air temperature is kept at 25-27 degrees.

Advice! It is always recommended to increase the temperature by a couple of degrees, taking into account the mode indicated on the package with tomato seeds. This promotes faster plant development and an earlier harvest.

In such conditions, it is impossible to keep the seedlings for too long - the tomatoes can easily rebuke and die. Therefore, as soon as the first sprouts appear, the film is removed, and the containers with tomatoes are placed in a cooler but brighter place. The temperature there is maintained at 20-22 degrees.

At this stage of development, tomato seedlings need an alternation of night and day temperatures, so at night the thermometer should show a few degrees less - the optimal value is considered to be from 16 to 18 degrees.

After the tomato seedlings have been dived, you need to maintain the same temperature regime and the alternation of night and day temperatures, but at this time you need to start gradually hardening the seedlings.

Correct hardening of tomato seedlings

Before planting a tomato in a permanent place (in a greenhouse, greenhouse or in open ground), the seedlings must be hardened.

Important! Self-cultivation of tomato seedlings has a lot of advantages, one of which can be considered the fact that the owner is confident that the plants are ready for new conditions.

But when buying tomato seedlings, you can never be sure that they, in general, have been hardened.

Hardened tomato seedlings are much stronger and more adaptable than usual - such tomatoes will quickly get used to the new external environment, very soon they will begin to give new shoots and roots, form ovaries and give a harvest. The likelihood that plants that have not been hardened will be able to take root in a new place is extremely small, this is possible only in a very warm climate and with normal humidity.

You need to start hardening tomato seedlings as early as possible. Only picked tomatoes with one or two real leaves can be safely taken out on the balcony or in the yard. But this is possible only in one case: if the air temperature does not drop below 15 degrees.

Rarely is the spring so warm that in late March and early April the thermometer reads more than 10 degrees in the afternoon. therefore many summer residents and gardeners use the same greenhouses for hardening seedlings, where tomatoes will subsequently be transplanted. During the day, the air in the greenhouse warms up enough, and you can protect the plants from the cold earth by lifting them on shelves or benches.

When the night frosts have passed, and the air at night will be warm (about 8-10 degrees), you can begin the night hardening of tomato seedlings.

However, you should not put pots and boxes with plants directly on the ground; it is better to raise them on window sills or special shelves.

Important! The task of the hardening process is to accustom the tomato to a gradual decrease in temperature.

Therefore, this procedure should be carried out in several stages: they start with a slightly open window, then take out the seedlings for a few minutes, then leave the tomatoes on the street for the whole day, only after that they proceed to night hardening.

Moving tomato seedlings to the greenhouse

The greenhouse is needed in order to accelerate the ripening of tomatoes. After all, seedlings are transferred to protected ground much earlier than to simple beds. Polycarbonate, glass or plastic wrap allows the sun's rays to pass through the greenhouse, but at the same time prevents heat from escaping.

Thus, a certain microclimate is created inside the greenhouse, constant temperature and humidity are maintained - all this is very useful for tomato seedlings. In such conditions, plants develop rapidly, create ovaries and form fruits.

But, if the air in the greenhouse warms up quickly enough (already in March the temperature may be sufficient for growing tomatoes), then the earth becomes not much warmer than that in simple beds.

To speed up the process of warming up the greenhouse, you can use one of the following methods:

  1. Equip ground heating with electricity, warm water or other volatile systems.
  2. Raise the beds 40-50 cm from ground level, thereby protecting the tomatoes from ground frosts.
  3. Create warm beds, using the natural processes of decay and fermentation, pouring compost or humus on the bottom of the trench, and planting tomato seedlings on this layer.

When the ground in the greenhouse becomes warm (at 10 degrees), you can safely plant tomatoes.

Do not forget that too hot air is destructive for tomatoes; in order to maintain a normal microclimate, it is necessary to open the vents, use ventilation or tuck the film walls of the greenhouse.

The timing of planting a tomato in the ground

To calculate the correct timing for planting tomatoes in the ground, as mentioned earlier, you need to take into account several factors at once. But even after that, there is a high probability of the return of cold weather, frost or other surprises from the weather.

No one is immune from mistakes, which is why experienced gardeners never plant all their tomato seedlings in one day - this process is stretched by dividing the total number of plants into several parts.

If we talk about a strip with a temperate climate, then the first batch of tomatoes is planted here at the end of April (April 20 - May 1). The largest part of the plants should be planted in the medium term - May 1-10. And finally, tomato seedlings are planted in the middle of the month (10-20), trying to protect at least part of the crop from possible frosts.

Because of such difficulties in the calculations, it is possible to recommend summer residents to annually write down all the dates when tomatoes are sown for seedlings, dive, transferred to the ground, what kind of crop is harvested - this statistics will help determine the most optimal timing for planting tomatoes in a particular locality.

All farmers strive for one thing - to grow a tomato crop as early as possible and collect a record number of fruits. The haste in this process is not connected with the ambitions of gardeners - the earlier the tomatoes ripen, the less chances they have of contracting a fungal infection, suffering from insect pests, catching a period of intense heat or "surviving" until the autumn cold.

Today there are many ways to prepare the beds, aimed at taking tomato seedlings into the ground a little earlier. It can be:

  • high beds from wooden boards or other materials at hand;
  • planting tomatoes in straw or sawdust;
  • use for seedlings of individual containers (pots, buckets, boxes, bags);
  • warming the earth with compost, food waste, humus or other suitable substrates;
  • covering planted tomatoes with foil or agrofibre, used only at night or in bad weather.

Saving seedlings from frost

Despite all the precautions and complex calculations, it often happens that frosts take gardeners by surprise. And then it is necessary to accept urgent measures to save tomato seedlings in the open field.

There can be several such methods:

  1. Shelter with film or agrofibre, lutrasil and other special fabrics. For this method, it is recommended to provide a small metal arch or frame on which you can throw a covering material so as not to damage the tomato seedlings.
  2. Glass jars, plastic containers or even ordinary buckets can also protect tomatoes from freezing; another thing is that it is not always possible to find enough dishes. This method is more suitable for small areas with a couple of dozen bushes.
  3. If frost threatens a large tomato plantation, you can try to heat the plants with smoke. To do this, you need to light the fire from the windward side. As fuel, you must use what gives a lot of smoke: last year's foliage, wet thick logs, tree bark, wet sawdust. The smoke will travel along the ground, thereby heating the tomatoes.
  4. Severe frosts can threaten even tomatoes planted in greenhouses or greenhouses. There, the plants are also protected by sprinkling sawdust, straw on the bushes or covering them with cardboard boxes, plastic buckets, and bottles.
Important! The death of tomato seedlings occurs at a temperature of about +1 - -1 degrees. There are very cold-resistant varieties of tomatoes that can withstand a short-term temperature drop down to -5 degrees.

All this helps to make sure that specific dates for planting a tomato simply do not exist... Each gardener or summer resident must determine the planting dates empirically, observing their tomatoes for several seasons in a row.

Greenhouses or hotbeds can slightly facilitate the process of growing tomatoes, but such methods have their own characteristics. - a threat to plants is high humidity and the likelihood of overheating due to too high temperatures and insufficient ventilation.

Dealing with tomatoes, the farmer must understand that it will not be easy - the culture is very capricious and whimsical. But fresh tomatoes on the table and a good harvest fully pay off all the effort and money spent.

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