Content
Grapes are a southern culture. Thanks to the achievements of breeders, it was possible to promote it far to the north. Now growers harvest grapes in the northern regions. But only in a covering culture. Moreover, the acquired ability of grapes to endure severe frosts is directly related to the loss of large fruit and taste.
But in terms of their taste, they cannot replace table varieties. When choosing them, be sure to take into account the ripening time and the ability of the grape variety to resist adverse conditions.
There are no good table grape varieties that can withstand low temperatures without shelter. Many growers may disagree and will give examples of excellent overwintering of the vine under sufficient snow cover. Yes, this method justifies itself. But where is the guarantee that there will be a lot of snow in winter? Not everyone has the opportunity to throw snow on wintering vine bushes. Consequently, there is always a risk not only of being left without a crop, but also of simply losing valuable varieties. What conditions allow the grapes to successfully winter?
What temperature can grapes tolerate without loss?
If you do not take into account the not so many grape varieties that can not freeze even at -30 degrees and below, the temperature from -18 to -25 for the vine is considered critical, the specific numbers depend on the variety. Freezing of the soil below -7 degrees is dangerous for the roots of grapes.
Grapes are not only afraid of very low temperatures. No less destructive for the vine and its sharp vibrations. A prolonged thaw can trigger the process of the plant emerging from dormancy. Such grapes are capable of perishing even at temperatures that are much higher than critical.
The influence of the climate of the Volga region on the method of sheltering grapes
An important condition for successful wintering is the correspondence between the method of shelter and the climatic conditions in which the grapes grow. The following indicators must be taken into account:
- record minimum temperatures for the area in winter;
- the presence and height of snow cover;
- wind direction and strength;
- frequency and duration of thaws.
The Volga region is a large region, its climate in different regions is very different. But in general, it is characterized by a fairly cold winter with average temperatures from -10 to -15 degrees. At the same time, the temperature minimum in some areas exceeds -40 degrees. And this is with a small height of the snow cover.
How to shelter grapes for the winter in the Volga region? This is not so difficult to do.
Success can be achieved if the following conditions are met:
- properly prepare the vines;
- choose the optimal time for sheltering grapes, depending on the weather;
- choose the best way to cover the grapes in each specific case.
Preparing the vine for wintering
Oddly enough, it begins in the spring. The shelter removed in time will save the plants from spring return frosts, thereby allowing the grapes to retain all their strength for flowering, harvest formation and vine ripening. Agrotechnical techniques, carried out on time and in full, also contribute to this.
Too much stress on the bush can significantly weaken the vine.
One of the conditions for successful overwintering is the complete ripening of the vine. No matter how the unripe shoots of grapes are covered, it will not be possible to preserve them in winter. Therefore, you need to take care of this in advance. There are grape varieties in which by autumn all the shoots ripen completely, even without the participation of the grower. The rest will have to take care of and pinch all the green shoots back in August in order to achieve their full ripeness before frost.
There are a number of important activities that need to be done before the frost starts:
- dry land freezes much more strongly, therefore, water-charging watering of grapes in autumn is mandatory, the earth must get wet to the entire depth of its roots;
- top dressing with potassium-phosphorus fertilizers in September will make the bushes more frost-resistant, allow the vines to ripen faster;
-
after leaf fall, cut out all unripe shoots, in accordance with the rules for forming a bush;
be sure to leave 2-3 spare buds on each shoot, pruning should be done only at positive temperatures, otherwise the vine becomes fragile and breaks easily. First-year bushes are not pruned. - treat the grapes with antifungal drugs, for example, copper sulfate according to the instructions;
- remove the vines from the trellises and tie them into loose bunches.
The covering material also requires preparation: it is disinfected, the worn out is thrown away and a new one is purchased.
Choosing the timing of the shelter of grapes
It is important to do it on time. If you cover the bushes earlier, the buds may die from damping or get sick with fungal diseases. In autumn, there is an active process of accumulation of nutrients in the roots of grapes. They will help the plant withstand all winter hardships. Therefore, every day is important - you should not rush to cover. In practice, the signal for its beginning is the first frost on the soil.
The weather is unpredictable, the unheated roots of the grapes will freeze out before you cover them.
To successfully overwinter, the vine needs to undergo natural hardening. Its initial stage falls for the period when the temperature is in the range from +10 to 0 degrees. The final stage is for a period when the temperature is kept within the range from 0 to -5 degrees. The duration of each is at least a week. The transition to new conditions of existence should take place gradually, so as not to cause stress in plants. This is another reason not to cover the vines ahead of time.
How to properly cover grapes
There are many ways to hide. Let's try to figure out which one is most suitable for the Volga region. Rather severe natural conditions do not allow the use of partial measures. The vines only require complete cover.
No matter how you are going to cover the grapes, you need to start this process from the root zone, since it is most sensitive to the action of subzero temperatures.
A dead root system cannot be restored. Such a bush is irretrievably lost.
In order for the roots of the grapes to be comfortable in winter, you need to cover the root zone with a diameter of at least 50 cm with a layer of earth, or better with humus, with a height of at least 20 cm. The method of hilling is not suitable for this. We'll have to take the land from other beds, which did not have plants affected by fungal diseases.
It is especially important to insulate the roots of grapes on sandy and sandy loam soils, as they freeze more. To prevent this from happening, sheets of cardboard are additionally laid around the bushes or the ground is sprinkled with a layer of coniferous litter.
Shelter for the grape bush itself must meet the following criteria:
- protect from frost;
- prevent the accumulation of moisture;
- smooth out temperature drops;
- prevent rodents from damaging the bushes;
- protect from sunburn in early spring.
Sometimes the reason for the death of grapes is not severe frosts, but the drying out of the eyes due to high humidity. Therefore, the shelter must be dry and provide air circulation at temperatures close to 0. The following scheme is best suited:
-
the associated vines are laid on the boards laid under the bush, you can use scraps of plastic, the main thing is that the substrate is dry;
-
covered with dry sawdust or dry leaves treated from the fungus.
Take care of rodent poison and rodent repellents. Elderberry branches and a small container with diesel fuel poured into it, a special poison bought in a store, will do. -
they put low arcs and cover them with a film on top, which is well pressed so that they are not blown away by the wind, the gap between the sawdust and the film should be about 10 cm, and air must be left along its edges. With the onset of winter, everything will be covered with snow, and while there is no severe frost, air will flow into the vents, preventing the grapes from drying out. Instead of film, you can use cut sugar bags.
With a membrane effect, they release moisture to the outside, but prevent it from penetrating inside.
Some growers use film prepared as follows. Buy it in the form of a sleeve. Cut into pieces of the required length, peel them and put pieces of cardboard between the layers.
Reed mats have proven themselves well. They keep warm well. Their only drawback is fragility.
You can do the following in the vineyard:
- carry out all the preparatory activities as usual;
- lay the connected vines on a dry lining of boards or plastic, fasten with hooks;
- cover with white covering material, folded in half so that it lies in a loose layer. The white color protects the bushes from burns, and the loose layer of spunbond maintains a constant temperature;
- put low arcs and put a film on them so that small airflows remain, the distance between the film and the spandbond is no more than 10 cm;
Many growers simply add earth to the bushes for cover. This often gives a good result. But if there is a chance of water stagnation on the site, it is very possible that the vine will dry out during the snow melt.
Each grower chooses for shelter the method that is most suitable for his site and the varieties of grapes that are planted on it. More often than not, experience comes with time. You just need to carefully observe and draw the correct conclusions from your observations.
