Tomatoes in the greenhouse

Varieties of tomatoes for the greenhouse

Many summer residents believe that tomatoes in a greenhouse are good. In fact, life in closed ground for this culture is a real torment. Therefore, special requirements are imposed on greenhouse varieties.

Disease resistance. For normal development, tomatoes require air humidity in the range of 60 – 65%. It is especially important that the humidity, not higher, be at the time of flowering – otherwise the pollen will get wet and fertilization will not occur (1), which means there will be no harvest. But when the fruits begin to ripen, the humidity should be slightly higher – 75 – 85%. But in greenhouses, the humidity is always higher and sometimes reaches 100%. For tomatoes, this is not very good, but for pathogens, these are ideal conditions! Phytophthora especially likes this climate. Therefore, tomato varieties intended for greenhouses must be resistant to this disease. And hopefully others too.

Shade tolerance. As you know, tomatoes are photophilous plants. And, it seems, they should be quite comfortable in the greenhouse, because she made them transparent glass or polycarbonate. But it’s not. Glass, for example, “eats” 7% of the light and absorbs the ultraviolet that plants need. And polycarbonate takes even more – 13% of illumination with a sheet thickness of 4 mm.

Heat resistance. Tomatoes do not tolerate heat well. If the air temperature rises to 30 ° C, the pollen becomes sterile and there will be no harvest. And in closed greenhouses on sunny days, it rises by 10-20 °C above the outside air temperature (2). And if the yard is 25 ° C, then in the greenhouse it can be all 45 ° C!

So not all varieties are suitable for a greenhouse. There is no point in listing greenhouse options by name, because the list will be very long – there are many such varieties. And you can find out which of them are suitable for greenhouses by reading the information on the bag with seeds – it is always indicated there.

If you have your own seeds, look at the description of the variety in the State Register of Breeding Achievements – this information is also indicated there.

Caring for tomatoes in a greenhouse

Features of closed ground leave their imprints on the care of tomatoes. And in order to get a decent harvest, it is important to comply with a number of conditions.

Shine. Tomatoes, as we have already found out, are photophilous. They must be lit from morning to evening, so it is important that the greenhouse is in an open area. And glass (polycarbonate) must be thoroughly washed. Even if you have planted special varieties that are resistant to low light, this does not mean that they can grow in the shade – they still need light. Otherwise, flowering will be delayed, the crop will begin to ripen later and fewer fruits will be formed.

Temperature. The optimum temperature for tomatoes is 22 – 25 ° C during the day, 16 – 18 ° C at night. If the temperature is above 30 ° C, pollen, as already mentioned, becomes sterile and you can forget about the harvest. But what if the temperature rises? The solution is simple – to ventilate the greenhouse. Tomatoes are not afraid of drafts, so you can safely open both doors and windows.

But here, too, there is a trick. If you open the greenhouse at noon, the difference between the temperature inside and outside will be very large, the tomatoes will be stressed. Therefore, it is necessary to ventilate as early as possible, no later than 8 in the morning.

Some summer residents try to lower the temperature by watering, as they do in the open field, but this will not help the tomatoes in the greenhouse. But it can do harm, because high humidity is the cause of phytophthora and brown spotting.

Watering tomatoes in a greenhouse

Features of the greenhouse dictate the rules of irrigation.

Tomatoes should be watered indoors only in the morning, so that excess moisture evaporates by evening.

Until the moment when the fruits begin to set, watering should be moderate, but the top layer should be constantly wet.

When the tomatoes begin to pour, watering is increased – it should be plentiful. Otherwise, the flowers will begin to crumble. But here one more point is important – watering at this time should be uniform. Otherwise, the fruits will crack.

And do not forget to cut off the lower leaves, even healthy ones – you need to remove everything up to the first flower brush – they become polluted when watering and become a source of disease, because pathogenic spores are in the soil. However, you can not remove all the lower leaves – you need to stretch this procedure for a week, breaking off every 2 to 3 days. And this should be done in the morning (3).

Top dressing of tomatoes in the greenhouse

If you filled the greenhouse with fertile soil, then for the first time the tomato will be enough batteries.

And then they will need to be fed 2 times:

• when the fruits gain weight – 1 matchbox of ammonium nitrate and potassium sulfate per 10 liters of water, consumption – 3 liters per bush.
• 20 – 30 days after the first – the same fertilizers in the same doses.

In a greenhouse, it is very important to observe the doses of fertilizers. In no case should they be increased, because the volume of soil in the greenhouse is usually limited, and all excess fertilizer will remain in the root zone (in open ground they are washed into the lower soil layers). And they can poison plants.

Popular questions and answers

In general, growing tomatoes in a greenhouse is a simple matter. But problems still arise. And as a rule they are typical. Let’s take them apart with agronomist-breeder Svetlana Mikhailova.

Sources of

1. Fisenko A.N., Serpukhovitina K.A., Stolyarov A.I. Garden. Handbook // Rostov-on-Don, Rostov University Press, 1994 – 416 p.
2. Romanov V.V., Ganichkina O.A., Akimov A.A., Uvarov E.V. In the garden and in the garden // Yaroslavl, Upper Volga book publishing house, 1989 – 288 p.
3. Ilyin O.V. and a group of authors. Vegetable grower’s guide // M.: Rosselkhokhizdat, 1979 – 224 p.