Winter cold in Polish climatic conditions can be treacherous – even varieties considered resistant need well-thought-out protection to be in full swing again in spring. Recent field analyzes conducted by the State Plant Health and Seed Inspection Service confirm that that adult bushes of varieties such as Solaris or Riesling are able to survive temperature drops to -24 ° C, and in favorable conditions even to -26 ° C. In their case, a relatively simple form of protection is enough: a mound of earth at the base of the trunk and a layer of mulch, which effectively insulate the roots, maintaining their temperature at a safe level and minimizing the risk of frost.
The situation is completely different in the case of young plantings. The first three years of a bush’s life are the critical period when the plant is most susceptible to frost damage. During this time, the lack of appropriate protection may result not only in partial losses in the form of frozen shoots, but even in the complete loss of the plant. Even a small episode of severe frost, which is only a minor stress for a mature bush, can mean dramatic consequences for a young seedling.
Grafted vines also require special attention. The characteristic thickening at the base of the trunk, which is the junction between the rootstock and the noble variety, is its critical point – a real “Achilles heel”. Damage to this zone almost always leads to the complete loss of the plant, regardless of the further condition of the shoots or leaves. Therefore, in the case of young and grafted bushes, a 20-30 cm high mound is not just a recommendation, but a necessary practice.. Additionally, it is worth remembering that a thicker layer of mulch or compost will protect sensitive places against low temperatures, but will also stabilize soil moisture and limit thermal fluctuations that may stress the plant during the winter dormancy period.
In autumn, the vines begin to prepare for winter dormancy. For this reason in October and November It is particularly important to water plants growing on light and sandy soils, because they quickly lose moisture and may lead to dry roots.. Maintaining stable soil moisture supports the carbohydrate metabolism of vines – as a result, the vines accumulate more energy in the form of sugars and starches, which increase their resistance to low temperatures. Well-watered plants in autumn enter winter in optimal condition, and in spring they regenerate faster and start the new season in full strength.
At the same time, you cannot forget about tidying up the space around the bush. By removing weeds, fallen leaves and organic debris, we reduce the risk of developing pathogens that could attack both shoots and roots in humid conditions.. At this stage, it is also worth considering laying down a layer of mulch made of bark, compost or dry leaves, which provides natural insulation – it stabilizes the soil temperature and maintains moisture in the root zone, limiting thermal fluctuations that could damage sensitive tissues.
In autumn, we should also remove the thin, not yet woody ends of the shoots. Longer shoots can be shortened to make it easier to cover them later with agrotextile or a mound.. Fresh cutting wounds should be protected with horticultural paste, which limits the penetration of pathogens and significantly reduces the risk of fungal infections in the following months.
The best time to cover the vine is just after the leaves fall, when the temperature drops to about -2 °C to -4 °C — then the bushes enter a state of rest and are less susceptible to mechanical damage. During this period, you can safely start forming the mound and installing protection – acting too early may disturb the natural acclimation cycle, and subsequent covering may be less effective. To properly protect the vine in winter, we can also use:
- mound of soil or compost (20-30 cm high) around the trunk: protects the foundation of the plant, i.e. grafting, and the lower buds, which are responsible for the regeneration of the bush in spring. Compost or a well-formed layer of earth additionally stabilizes soil moisture and supports microbial life in the root zone, which translates into the ability of the vine to successfully go through the winter dormancy period. On light and sandy soils, the mound also serves an insulating function, protecting the root system against rapid cooling and excessive temperature fluctuations;
- winter agrotextile for younger or sensitive plants: in the case of young vines and less resistant varieties, agrotextile is an effective barrier against frost. To maintain its functionality, the material should not fit tightly to the shoots. It is best to build a light frame with hoops or slats, thanks to which the non-woven fabric will create a loose “coat” surrounding the bush. However, you should leave gaps at the bottom of the cover to reduce the risk of moisture. This solution protects the plant against winter mold and prevents the shoots from “scalding”;
- straw or coconut mats: if we attach them to supports, we will gain an insulating layer that protects the bush against low temperatures and wind. Thanks to their natural structure, the mats retain air at the plant surface, additionally increasing thermal insulation;
- spruce branches as additional insulation: It is worth placing spruce branches on top of the mat or agrotextile. They act as a natural “quilt”, retaining snow, which acts as an additional air cushion, and at the same time protects against wind and cold. Spruce absorbs part of the wind energy, creating a stable and safe microclimate zone around the bush;
- screen from the north side: in locations where cold north winds prevail, an effective solution is to place a simple screen. This can be a light mesh or thin boards placed on the side from which the coldest wind blows. The screen reduces the cooling of plants, protecting their shoots and grafting against direct exposure to frosty gusts.
During winter thaws, keep the sides of the fabric slightly open. This allows fresh air to enter and reduce the humidity inside the cover. If the cover is loaded with snow, we should remove it, because wet fluff may damage the structure or crush the shoots, causing deformation.
In spring, we remove the covers in stages, usually when the frosts subside but the ground is still cool. The first step is to open the sides of the cover, then remove the roof and finally the agrotextile. This process allows the buds to gradually harden off – sudden exposure on a warm, sunny day can stimulate sap circulation and expose the plants to later frost damage.
