The temperature for tomato seedlings is an unstable constant that should change depending on the phases of plant development. By varying the temperature, you can suppress the rapid growth of tomato tops or cause intensive branching of the root system. Using the right temperature, you can stimulate seeds to accelerate germination or prepare seedlings for planting in the ground. For growing tomatoes, maintaining the desired thermometer level is no less important than timely watering or high-quality fertilizing.
Thermal preparation of seeds
Thermal treatment of tomato seeds is not among the mandatory procedures for growing crops and not all manuals include this point, but it has been noticed that tomato seeds that have been heated germinate more quickly and form a stronger sprout than unheated seeds. Procedure options preparing tomato seeds depend on the preferences of the owner of the summer cottage. Let's name the main methods of temperature influence on tomato seeds:
- “winter” method, used at the end of March - tomato seeds are tied into a knot using a simple handkerchief and hung next to a central heating radiator until the very moment germination begins - until April - May;
- Place a clean sheet of paper on a table lamp cap turned upside down, and sprinkle tomato seeds in a thin layer; warming up time - three hours with periodic mixing of seeds;
- To make the seeds germinate faster, use an oven preheated to 50-55 0C, in which a baking sheet with tomato seeds is placed for two hours;
- heating with water is used immediately before germinating the seeds - for this they are wrapped in a fabric bag and immersed in hot water for 2.5-3 hours (50-55 0C) water; During this time, hot water is added so that the optimal temperature is maintained.
Warming up the seed material has an impact on the quality of germination and speeds up the time of harvesting, the tomato grows faster, however, to resist diseases and prevent a negative reaction of tomato seedlings to possible cold snaps or excess (lack of) moisture, they use the opposite method of thermal preparation - hardening of tomato seeds at low temperatures.
For the procedure, tomato seeds need to be placed in a saucer, filled with water, covered first with gauze, and then with cellophane and placed in the freezer for a day. In this case, the temperature should not be higher than -1 0C and not lower than -3 0C. Then contrast is performed by transferring the frozen tomato seeds for another day, at normal room temperature. In total, hardening using similar methods is carried out two to three times. During processing, tomato seeds may germinate, and after this happens, hardening is stopped.
At what temperature should you germinate seeds?
A month and a half before the start of the summer season and the time when the tomato seedlings will need to be transplanted into the ground, the sprouted tomato seeds are planted in seedling containers. From this moment until the first sprouts peck, the optimal temperature for germination of tomato seeds is considered to be 21-23 0WITH.
Under these temperature conditions and good soil moisture, you can see the tomatoes sprouted after just a week.
When this happens, the boxes with seedlings are placed on the brightest windowsills of the house or in the brightest areas of the greenhouse and try to lower the overall temperature to critically acceptable levels while the tomatoes germinate. During the day, the minimum temperature for seedlings is now 13 0C, and at night 11 0C. Similar to acclimatization, during the beginning sprouting tomatoes, must be completed, since the procedure is responsible for the correct reaction of young plants to the effects of low temperatures above zero.
The next important step in growing tomato seedlings is picking the seedlings into separate pots.This procedure is stressful for fragile plants, so preparation for it begins 3-5 days before the manipulations and consists of placing the seedlings in a temperature reduced to 17 0C. If the climate is controlled by opening and closing window transoms, care must be taken to ensure that the tomatoes are not placed in a drafty area.
The appearance of cotyledon leaves serves as a signal that tomato seedlings are ready for picking. Tomato seedlings are buried in pre-prepared containers down to the leaves and watered with water kept at room temperature for three days. Then the tomatoes are shaded, without limiting the passage of ventilation sufficient for healthy growth, and the cover is removed only after three days, when the plants have taken root well.
After picking, the temperature for growing tomato seedlings is lowered, bringing it closer to those indicators that corresponded to the care of newly germinated seeds - that is, during the day, it will be 19-21 0C, and at night 12-14 0C. Such competent adjustment will subsequently allow the formation of abundant flowering with a rather modest development of greenery to the lower fruit cluster.
What temperature is needed to plant seedlings in the ground?
After the appearance of the fifth leaf, it is no longer rational to keep the seedlings in a pot, as they begin to rapidly grow and form tops. 10-14 days before transplanting to a permanent place, tomato seedlings are hardened by gradually approaching conditions that will become the norm for the plant and, accordingly, should not cause discomfort.
To begin hardening before planting, choose a warm day without precipitation.Tomato seedlings are placed in a greenhouse with the frames removed or on a balcony for half an hour, the next day for an hour, and so on, bringing the time the plants spend in the air to six hours. Three days before transplanting, the seedlings should be left in the greenhouse overnight.
You can move plants into open ground only when the risk of frost in your region is reduced to zero. Any sub-zero temperature for tomato seedlings is detrimental, as is too high (more than 30 0C), although the degree of resistance to heat increases in the plant as it approaches maturity.
The optimal temperature for seedlings is well maintained in the greenhouse, but here it is more important than protecting the tomatoes from the cold, it will be to prevent the plants from overheating. If you do not periodically open the frames or leave the door ajar, tomato seedlings may simply bake in the created microclimate.
You can regulate the temperature by spraying, using urea diluted in water in a weak concentration - 2 teaspoons of urea per bucket of water. This solution also stimulates the development of the bush, and tomato seedlings grow faster.
Saving tomatoes from summer heat and spring frosts
Tomato seedlings planted in open ground are especially dependent on the influence of sunlight, which affects not only the plants, but also the soil, drying it out and damaging the root system. You can prevent cracking of the soil and “attract” the maximum possible amount of moisture to the tomato seedlings, in the form of morning dew, by mulching with straw or freshly cut weeds. On the side from which the sun's rays scorch the beds during daylight hours, it is necessary to create a natural shield over the tomato seedlings in advance by planting corn, Jerusalem artichoke or sunflowers.
When growing tomato seedlings, it is important not to rush into transplanting into open ground, correctly assessing the possible weather vagaries of your region. But it happens that frosts come in mid-June, when tomato seedlings are already beginning to produce fruit clusters and the entire harvest is at risk. In this situation, you need mobile and quickly installed protection in the form of aluminum arches, over which the film is stretched. If frost falls on the soil shortly after transplanting tomato seedlings, you can protect the plants individually by building a temporary cap over each one from a plastic bottle with the neck cut off.
As can be seen from the article, protecting tomato seedlings at a temperature level is no less important than moistening the soil or creating a comfortable growing environment. Starting from the moment when the seed germination temperature is at the forefront of the process of planting the future crop and ending with the careful protection of growing plants from the heat and cold of an open area, it is maintaining the optimal thermometer scale that will help preserve the tomato harvest and make it an object of admiration among others.
