How to properly water tomatoes in a polycarbonate greenhouse

Polycarbonate greenhouses are becoming more and more popular with gardeners every year. Especially often they are used for growing tomatoes. But in order to harvest a good tomato crop, you need to know how to water them properly.

Greenhouse microclimate

Greenhouse microclimate

If we compare polycarbonate greenhouses with film or glass structures, then they have a number of advantages:

  • compared to glass structures, polycarbonate retain heat up to 30 percent better;
  • such material perfectly transmits light and at the same time protects tomatoes from sunburn;
  • this greenhouse is more airtight, so inside it the risk of drafts or sudden temperature changes is minimal.

However, these advantages, in some cases, can become, on the contrary, disadvantages that negatively affect the microclimate of the greenhouse. For example, good tightness and thermal insulation of the structure can cause a strong increase in temperature and humidity.

Tomatoes grow best at humidity – about 50-60% and at a temperature – from 23 to 29 degrees. And in such a greenhouse in the summer, with improper care, the temperature can reach 45-50 degrees, and the humidity can rise to 90% or more. This has an extremely negative effect on the growth and development of tomatoes.

And in such conditions, the likelihood of developing fungal diseases is high. To avoid such problems, you will need to install a ventilation and heating system in the greenhouse, you can also resort to ventilation, but in this case, the plants may suffer from sudden temperature changes.

In order for the cultivation of tomatoes in such a greenhouse to be successful, one must carefully monitor the temperature and humidity of the air, and also do not forget to disinfect in a timely manner.

Humidity rate for tomatoes in the greenhouse

The yield of tomatoes grown in a polycarbonate greenhouse depends both on temperature and on the level of humidity in the air and soil. At the same time, the optimal air humidity is about 50–60 percent, and the soil is about 90 percent. In this case, the tomatoes will grow and develop normally, and they will also be protected from fungal diseases.

How often to water tomatoes in a greenhouse

How often to water tomatoes in a greenhouse

The frequency of watering tomatoes grown in greenhouse conditions plays an important role in their development and fruiting. Both overflow and lack of moisture can equally harm such a culture, in which case the bushes begin to hurt, which has an extremely negative effect on the quality and quantity of fruits.

You can understand that the selected irrigation mode is incorrect by the following signs:

  • all leaf plates on the bush lose turgor and begin to fly around due to insufficiently frequent or too poor watering;
  • twisted foliage is a sign that watering is very frequent or excessively plentiful.

On average, tomatoes that grow in a greenhouse are watered 1-2 times a week. In this case, the frequency of irrigation is affected not only by temperature, but also by air humidity.

Features of watering tomatoes in a greenhouse

Experienced gardeners know that the frequency and abundance of watering tomatoes grown in a greenhouse depends on what stage of development the bushes are at.

After disembarkation

After disembarkation

After the seedlings are transplanted to the bed in the greenhouse, it should be well watered with plenty of water. The transplanted seedlings are at first in a depressed state, and their root system is still very weak, so soil moisture during this period should be given special attention.

However, there is no consensus on this matter:

  • Some experts advise watering the planted seedlings daily, using a small amount of water for this, arguing that a weak root system is not able to absorb too much liquid, and since it has not yet grown, it is not able to extract moisture from deeper layers. soil.
  • Other experts are sure that after the bushes are abundantly watered after planting (4-5 liters of water per bush), they should be left alone for a week. During this time, they will have time to take root, and their root system will become stronger.

During active growth and flowering

During active growth and flowering

When the seedlings take root and begin to grow actively, the frequency of irrigation should be such that the soil surface between them has time to dry to a depth of 30–50 mm. As a rule, at this time the soil is moistened 1 time in 5 days.

If you water the tomatoes more often, then only the superficial root system will develop well, which is not able to provide the plant with all the necessary nutrients. The same irrigation regime is provided to this vegetable crop during flowering.

During fruiting in July-August

During fruiting in July-August

During the period of fruit set, the number of waterings is increased. The fact is that at this time the bushes spend a lot of moisture on the growth of fruits, however, if there is too much liquid in the soil, this can cause them to crack.

Make sure that the soil is constantly slightly moist, but at the same time, water should not be allowed to stagnate in the root system. On average, at this time, watering is carried out twice in 7 days.

However, if the surface of the earth near the bushes is very wet, then the number of waterings can be reduced to 1 time in 5 days.

When the fruits grow and begin to sing, the watering regime should be changed again. If the bushes are watered too abundantly and often at this time, then ripening tomatoes will not only crack, but also begin to rot. As a rule, at this time the earth is moistened 1 time in 1–1,5 weeks.

Read more in the article: How to water tomatoes in the open field

How to organize watering with your own hands

There are several ways to water tomatoes grown in a polycarbonate greenhouse. Each of them has its own advantages and disadvantages. The most common of them will be discussed below.

Manual watering

Manual watering

If the greenhouse is small, then it is recommended to use the manual method for watering tomatoes. To do this, you will need either a watering hose or a watering can, while water must be poured under the root.

The disadvantage of using a watering hose is that in this case the water comes either from the water supply or from the well, and it is very cold, so the likelihood of hypothermia of the root system increases. And this method is also bad because it is impossible to control the amount of water poured under the bush.

Experienced gardeners recommend using a watering can in this case. In this case, it is better to take water settled and heated in the sun. To do this, you can install a barrel near the structure, into which water is poured in advance so that it has time to heat up.

Drip irrigation

Drip irrigation

Drip irrigation is advantageous to use in large greenhouses, since manual irrigation in this case is too complicated and takes a lot of time.

This method has many advantages:

  • the liquid enters immediately to the root system, so it does not evaporate on the soil surface, which means that watering will not contribute to an increase in air humidity;
  • water will not fall on the surface of foliage, shoots or flowers;
  • You can water tomatoes at any time of the day;
  • the soil during irrigation is not salted and is not washed out.

To provide plants with drip irrigation, you will have to install a special system, which is a set of special tubes connected to each other, they are brought directly to the roots of plants, and it is through them that water enters.

The easiest way is to purchase a ready-made drip irrigation system in a specialized store, but if you wish, you can assemble it yourself.

How to organize drip irrigation in a greenhouse – video

Pit irrigation

Pothole watering of tomatoes is a rather unusual method that some gardeners are just starting to use.

  1. In this case, a hole is dug in the bed with a depth of 0,3 meters and 0,5–0,6 meters in diameter.
  2. Four tomato bushes are planted along the edges of this pit, while the distance between them should be from 0,5 to 0,6 meters.
  3. After planting, the hole must be filled with mowed grass so that it rises slightly above the surface of the bed.
  4. During irrigation, water is poured only into this grass, 20 liters of water are poured into one hole at a time.

This method is good because deep watering of the tomato occurs, due to which the root system of the bushes becomes strong and well developed. And over time, the cut grass begins to rot and warms the roots of the plant, which also has a positive effect on their development and growth.

And this method also allows you to reduce the amount of watering, the charge of moisture to the bushes can be enough for about 7-10 days (sometimes longer).

Watering with plastic bottles

Watering with plastic bottles

The method of watering a tomato using plastic bottles is very popular among gardeners. The fact is that the consumables in this case cost practically nothing, you only need a few plastic bottles, carnations and old tights.

It is very easy to build a structure from bottles, and it can serve you for more than one year. There are several options for such structures:

  1. Funnel. Take a bottle and make a few holes in its cork with a nail. If the soil on the bed is light, then make only a couple of holes in it with a diameter of about 0,2 cm, and if the soil is heavy, then 4 larger holes will be needed. The cork should be covered with unnecessary tights or other synthetic material (natural can rot). This is necessary so that the soil does not clog holes. Then cut off the bottom of the bottle, but not completely, make something like a cap. Install the resulting “funnel” in the garden between two planting holes to a depth of 15 centimeters and at an angle of 45 degrees, then fill the container with water.
  2. Down in the ground. In this case, holes are made on the sides of the plastic bottle, after which tights are put on it. Then the container is dug between two landing holes strictly vertically so that only the neck rises above the surface. It will need to pour water into it from time to time. It is impossible to close it with a cork, since in this case the liquid will not be able to leave the bottle and soak into the soil.

When to Water

When to Water

The time of watering tomatoes grown in greenhouse conditions directly depends on weather conditions and on the design features of the greenhouse. As a rule, if the weather is dry and warm, then you can water the tomatoes at any time except at night. But in this case, during the daytime, you need to pour water very carefully under the root so that it does not fall on the surface of the foliage, since the sun’s rays in this case can leave burns on the leaf plates.

Experienced gardeners recommend starting watering in the afternoon, because by this time the water in the barrel has time to warm up well, because it cools down overnight.

Please note that it is impossible to water the bushes late in the evening or at night, because the greenhouse is tightly closed at night and therefore the humidity of the air rises very much, which is detrimental to tomatoes.

If you decide to water the tomatoes in the evening, then ventilate the greenhouse well to remove excess moisture from it.

If the weather is cool and damp, then watering is carried out before lunch, in which case the structure will have time to ventilate well until the evening.

Tips from seasoned gardeners

If you first decided to start growing tomatoes in a greenhouse, then the advice of experienced gardeners will certainly come in handy:

  1. If you heat water for irrigation in a barrel and installed it inside the greenhouse, then be sure to cover it tightly with a lid or film. The same applies to any other containers filled with water. If this is not done, then the liquid will begin to evaporate, and this will significantly increase the level of humidity in the air.
  2. If the soil in the garden does not absorb water well, it is recommended to carefully dig it with a pitchfork.
  3. It is highly undesirable to regularly loosen the surface of the soil around tomatoes grown in greenhouse conditions. Instead, immediately after planting, it is better to cover the surface of the bed with a layer of mulch (hay or straw).
  4. In warm weather, the optimum temperature of the water used for irrigation should be from 18 to 20 degrees, and in cold weather – from 22 to 24 degrees. If the water is cold, then the tomatoes will experience stress after watering, which will negatively affect their growth and fruiting.
  5. Immediately after watering, be sure to ventilate the greenhouse well (if you do not have a ventilation system installed). Otherwise, the humidity of the air will rise sharply, which is highly undesirable.

Proper watering of tomatoes in a polycarbonate greenhouse – video

If you provide tomatoes growing in a polycarbonate greenhouse with the correct watering regime and maintain optimal soil and air humidity, and do not forget to monitor the temperature, then the chances of harvesting a rich harvest increase many times over.

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Anna Evans

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