Growing tomato seedlings involves many stages, one of which is hardening. For plants that have been pampered in the warmth of home, a sudden move to the beds can be too serious a test. Most tomatoes without preliminary preparation will not be able to survive the adaptation and will die or be noticeably retarded in development.
Hardening will help seedlings:
- build a powerful root system;
- acquire a dense epidermis;
- accumulate the required amount of sugars;
- prevent pulling.
Hardened tomato seedlings are noticeably different from their “spoiled” counterparts that have not undergone preliminary preparation. If you have to buy tomatoes at the market, then you must definitely choose bushes with signs of hardening:
- the plants have a strong appearance;
- well covered with hairs;
- the color of the tops is dark with a purple tint on the stem;
- internodes are short, bushes are squat.
Hardening measures
Hardening of seedlings is a gradual preparation of plants for the climatic conditions of open ground. There are no large jumps in temperature and humidity in the apartment. Sudden changes in conditions after transplantation can destroy tomatoes.
Therefore, over 2-3 weeks, tomato seedlings begin to gradually become familiar with the real conditions of the outside world.
Hardening with moisture deficiency
A week before hardening off the seedlings outdoors, begin to increase the time between watering the plants. Tomatoes need to get used to short dry periods. Therefore, the soil in the pots is allowed to dry out better so that the root tries to extract moisture from the entire lump of earth. This will give a signal to the plant to increase its root mass. But it is important not to overdo it during dry periods; tomatoes should not clearly suffer and wither. Tomato seedlings hardened by changes in humidity will be distinguished by a powerful fibrous root.
Hardening by temperature changes
On a warm spring day, when the air temperature has risen to 17-20 ℃, the tomatoes are taken out to a shaded place protected from the wind for 30-40 minutes. Every next day the time is increased by 1-2 hours. If the weather suddenly deteriorates in the first days of hardening and the temperature drops below 14-15 ℃, it is better to bring the plants into a warm place and simply provide good ventilation.
After a week of hardening, the seedlings are no longer afraid of cold snaps; tomatoes can be outdoors all day long. The main thing is that the temperature does not drop below 10 ℃.
At the end of the second week of preparation, the tomatoes can be left in an open area for a full day, allowing them to adapt to nighttime temperature changes.
Stressful conditions will slightly slow down the growth of green mass, but the development of the root system will increase. Tomatoes will quickly begin to develop a dense epidermis and “pull” hairs to withstand weather conditions. Internodes will remain short, strong bushes will not be overly elongated.
Hardening by direct sunlight
In the second week of preparation, the seedlings are introduced to direct sunlight. First, it should be in the morning or evening hours, when the rays cannot cause burns. Gradually increase the time the plants spend in a sunny place. Hardening tomatoes in direct sunlight helps plants after transplantation to easily adapt to the site without losing green mass
Important!
Pampered plants, not prepared for direct sunlight, quickly become burned, lose leaves and dry out.
Hardening in the greenhouse and on the balcony
If seedlings are grown in a greenhouse or hotbed, then for hardening, open all windows and doors, lift the film, comparing the temperature with the outside temperature. They also act gradually, increasing the time by 1-2 hours every day. We must not forget about preparing for direct sunlight. The diffuse light of greenhouses prevents plants from developing immunity to ultraviolet radiation. Therefore, the design of a greenhouse for growing seedlings must provide for raising the upper transoms.
To harden off tomato seedlings, some vegetable growers simply leave the plants on the balcony with the windows open. In this case, the seedlings should still spend the last 3-4 days in the future site. It is impossible to achieve real changes in temperature and humidity on the balcony; the preparation of tomatoes will be inadequate.
Hardening of seeds
When studying information about how tomato seedlings are hardened, you can come across recommendations for hardening the seeds before sowing. Tomatoes from prepared seeds grow cold-resistant, and the time required to obtain the first harvest is reduced. This hardening method is most often used in the northern regions of the central zone of our country:
- fold several layers of filter paper in a flat container and moisten;
- place tomato seeds on top and cover with a layer of damp paper;
- keep for a day at room temperature, regularly moistening the dried paper;
- put the dishes with seeds in the refrigerator for a day;
- the cycle is repeated again;
- The hardened seeds are immediately sown into the soil.
After such preparation, the seed sprouts very quickly, and subsequently the yield and disease resistance significantly increase.
