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To the question: “At what temperature can tomatoes be planted?” Even the most experienced gardener cannot give a definite answer. The thing is that tomato is a capricious crop and very heat-loving. To calculate the timing of planting tomatoes, you need to take into account a number of factors. And still, it is unlikely that you will be able to achieve an excellent result the very first time, because growing tomatoes is a process divided into several separate stages, each of which requires adjustment of all conditions, including temperature.
When is it necessary to plant tomatoes, and what do these terms depend on? Let’s try to figure it out in this article.
Temperature groups of tomatoes
Like any crop, tomatoes have their own growing season, which is directly related to the variety of the vegetable. 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 bag of seeds.
Of course, the manufacturer’s instructions are very approximate, but thanks to them, you can understand which temperature group a particular variety of tomatoes belongs to. And there are only three such groups:
- The first category includes the most cold-resistant varieties of tomatoes, which, as a rule, are tomatoes with early ripening periods. These crops are zoned for the climate of the northern regions, but can be used in the middle zone and in the south of Russia if 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 fall below 11 degrees, and during the day the heat is maintained at 15 degrees. This method of planting is good because the root system of the tomato can receive the maximum amount of moisture remaining in the ground after winter. In terms of time, this period falls approximately at the end of April - the first days of May.
- The timing of planting tomato seedlings belonging to the second temperature group coincides with approximately mid-May. By this time, the night temperature in the region should be at 14-15 degrees, while during the day the temperature is recommended to be no lower than 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 in danger of frost, and there is still enough moisture in the ground for the development of the root system.
- Tomato seedlings planted in the ground after the thermometer has stabilized at 20 degrees belong 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 bakes the tender leaves of young seedlings too much.In addition, late planting threatens tomatoes with various diseases and fungal infections. However, this method is suitable for the latest varieties of tomatoes. And in the northern part of the country, gardeners do not plant tomatoes in the garden before the end of May or even the beginning of June.
This significantly increases the chances of getting a good harvest; moreover, such a scheme will help determine the most favorable planting time for a particular tomato variety in a particular region.
Dependence of the timing of planting tomatoes on the speed of ripening
Everyone knows that tomatoes are early-ripening, mid-ripening and late-ripening. Such varieties have characteristic features and, of course, differ in the length of the growing season. The temperature required by tomatoes for normal development may also differ depending on the speed of their ripening.
Here is the following relationship:
- Late-ripening tomatoes and indeterminate tomatoes (tall) tomato hybrids are sown as seedlings from February 15 to February 25. 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 open ground corresponds to the first ten days of May.
- Medium-season tomato varieties ripening and the same hybrids must be sown for seedlings on March 5-10, and transferred to a permanent place somewhere around May 10-20.
- Seeds of early ripening varieties, as a rule, are sown from March 15 to 25; seedlings can be taken out under cover in mid-May, and into open ground not earlier than the first days of June.
These indicators are the main ones when calculating the timing of planting tomatoes.
At what temperature should you plant tomatoes?
The process of growing tomatoes is divided into several stages:
- preparing tomato seeds for planting;
- planting seeds for seedlings;
- picking tomato seedlings;
- hardening of tomatoes before planting in a permanent place;
- planting seedlings in open ground or in a greenhouse.
But even after all these stages, air and soil temperatures can significantly affect the development of tomatoes and their yield. Moreover The impact of both too low and too high thermometer readings can be negative.
It is under such conditions that irreversible processes begin in plants, leading to the rapid death of tomatoes.
Not only critical thermometer readings negatively affect tomatoes. For example, prolonged coolness at 16 degrees during the daytime will lead to the following:
- stopping the growth of side shoots on the tomato root system;
- inability to absorb minerals and moisture by roots;
- reduction in the number of ovaries and reduction in tomato yield.
Constant heat within 30-33 degrees also ends badly - tomatoes shed leaves and flowers, which leads to zero harvests.
The fight against cold is aimed at covering plants, so tomatoes are often grown in greenhouses, temporary greenhouses, and the seedlings are covered with agrofibre or plastic film at night.You can also prevent overheating of plants: shade the tomatoes, mulch the ground around the bushes to reduce the evaporation of moisture from the soil, and water the bushes often.
Preparing seeds and planting tomatoes for seedlings
To plant seedlings, you need to purchase or collect high-quality planting material yourself - tomato seeds. Before planting, the seeds are prepared in a certain way; one of the stages of preparation is hardening of the planting material: first, the seeds are heated, then placed in the refrigerator for several days.
Proper preparation helps prepare the seeds for harsh climatic conditions; seedlings obtained in this way will be able to withstand temperature changes and surges and will acclimatize better in a new place.
After the seeds have been sown, the containers are covered with film and placed in a warm place - the tomatoes will be able to germinate only when the air temperature remains at 25-27 degrees.
In such conditions, you cannot keep the seedlings for too long - the tomatoes can easily get stuck and die. That's why, 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 alternating night and day temperatures, so at night the thermometer should show several degrees less - a value of 16 to 18 degrees is considered optimal.
After the tomato seedlings have been planted, you need to maintain the same temperature regime and alternating night and day temperatures, but at this time you need to begin to gradually harden the seedlings.
Proper hardening of tomato seedlings
Before planting a tomato in a permanent place (in a greenhouse, greenhouse or open ground), the seedlings must be hardened off.
But when buying tomato seedlings, you can never be sure that they have been hardened at all.
Hardened tomato seedlings are much stronger and more adaptable than usual - such tomatoes will quickly get used to the new external environment, very soon begin to produce new shoots and roots, form ovaries and produce a harvest. The likelihood that plants that have not undergone hardening will be able to take root in a new place is extremely low; this is only possible in a very warm climate and with normal humidity.
You need to start hardening off tomato seedlings as early as possible. Only tomatoes that have been picked and have one or two true leaves can be safely taken out onto the balcony or into the yard. But this is possible only in one case: if the air temperature does not fall below 15 degrees.
It is rare to have such a warm spring that at the end of March and beginning of April the thermometer shows more than 10 degrees during the day. That's why Many summer residents and gardeners use the same greenhouses for hardening off 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 ground by raising them on shelves or benches.
When the night frosts have passed and the air at night is warm (about 8-10 degrees), you can begin night hardening of tomato seedlings.
However, you should not place pots and boxes with plants directly on the ground; it is better to raise them on window sills or special shelves.
Therefore, this procedure should be carried out in several stages: they start with a slightly open window, then take the seedlings out for a few minutes, then leave the tomatoes outside for the whole day, only after that they proceed to night hardening.
Moving tomato seedlings to the greenhouse
A greenhouse is needed to speed up the ripening of tomatoes. After all, seedlings are transferred to protected soil much earlier than to simple beds. Polycarbonate, glass or polyethylene film allow the sun's rays to pass inside the greenhouse, but at the same time prevent 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 quickly develop, create ovaries and form fruits.
But, if the air in the greenhouse warms up quickly enough (already in March the temperature can be sufficient for growing tomatoes), then the soil does not become much warmer than that in simple beds.
To speed up the heating process of the greenhouse, you can use one of the following methods:
- Arrange heating of the soil using electricity, warm water or other energy-dependent systems.
- Raise the beds 40-50 cm from ground level, thereby protecting the tomatoes from ground frosts.
- Create warm beds using the natural processes of rotting and fermentation, pouring compost or humus into the bottom of the trench, and planting tomato seedlings on this layer.
When the soil in the greenhouse becomes warm (at 10 degrees), you can safely plant tomatoes.
Do not forget that too hot air is detrimental to tomatoes; to maintain a normal microclimate, it is necessary to open the windows, use ventilation or tuck the film walls of the greenhouse.
Timing for planting tomatoes 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. But even after this, there remains a high probability of the return of cold weather, frosts or other weather surprises.
No one is immune from mistakes, which is why experienced gardeners never plant all their tomato seedlings in one day - this process is extended by dividing the total number of plants into several parts.
If we talk about a zone 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 middle period - May 1-10. And finally, tomato seedlings are planted in the middle of the month (10-20th), trying to protect at least part of the harvest from possible frosts.
Due to such difficulties in calculations, we can recommend that summer residents annually record all the dates when tomatoes are sown as seedlings, planted, transferred to soil, and how they are harvested - these statistics will help determine the most optimal dates for planting tomatoes in a particular locality.
All farmers strive for one thing - to grow a tomato crop as early as possible and harvest a record number of fruits.The haste in this process is not related to the ambitions of gardeners - the sooner the tomatoes ripen, the less chance they have of getting a fungal infection, suffering from insect pests, experiencing a period of intense heat, or “surviving” until the autumn cold.
Today there are many ways to prepare beds aimed at getting tomato seedlings into the ground a little earlier. It can be:
- raised beds from wooden boards or other available materials;
- planting tomatoes in straw or sawdust;
- use of individual containers (pots, buckets, boxes, bags) for seedlings;
- warming the earth with compost, food waste, humus or other suitable substrates;
- covering planted tomatoes with film 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 you need to accept urgent measures to save tomato seedlings in open ground.
There may be several such methods:
- Covering 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 covering material so as not to damage the tomato seedlings.
- 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 dishes in sufficient quantities. This method is more suitable for small areas with a couple of dozen bushes.
- If frost threatens a large tomato plantation, you can try heating the plants with smoke. To do this, you need to light a fire on the windward side.As fuel, you need to use something that produces a lot of smoke: last year's leaves, wet thick logs, tree bark, wet sawdust. The smoke will spread along the ground, thereby heating the tomatoes.
- Severe frosts can even threaten tomatoes planted in greenhouses or greenhouses. There, plants are also protected by pouring sawdust, straw on the bushes or covering them with cardboard boxes, plastic buckets, and bottles.
All this helps ensure that There are simply no specific dates for planting tomatoes. Every gardener or summer resident must determine the timing of planting experimentally, observing his tomatoes for several seasons in a row.
Greenhouses or greenhouses can make the process of growing tomatoes a little easier, but such methods have their own characteristics – a threat to plants is posed by increased humidity and the likelihood of overheating due to too high temperatures and insufficient ventilation.
When dealing with tomatoes, the farmer must understand that it will not be easy - the crop is very capricious and whimsical. But fresh tomatoes on the table and a good harvest completely recoup all the effort and money spent.
