How to properly cover grapes for the winter in the central zone and with what

The final activity in the list of autumn works in the vineyard is covering the grapes for the winter, which is required not only in the northern regions, but also and in temperate climates. Even frost-resistant varieties can suffer from sudden temperature fluctuations, winters with little snow, or excessive precipitation. It's impossible to give a definitive answer to how to properly protect grapes; the optimal covering methods and materials depend on specific growing conditions.

When and what kind of shelter is needed

Winter covering is necessary to protect vines and roots from freezing temperatures, cold winds, and excess snow. There are many options for winter covering for grapes, the choice of which depends on climate conditions and the condition of the plant.

Features of grapes

When choosing a wintering option, you need to consider the potential vulnerability of a particular bush:

1. Not all grape varieties tolerate cold equally well. Frost resistance indicators, specified in the variety description, will help determine the timing and density of covering.
2. Frost resistance in young plants is lower compared to mature bushes due to the thinner layer of bark.
3. A bush that has produced a large harvest is more susceptible to freezing than its less prolific peers, since fruiting uses up a lot of resources, weakening the vine.

Degree of protection

When it comes to providing shelter, don't rely on the principle of "the more, the better." It's not so much about isolating the grape vines from cold air as it is about providing optimal winter conditions; otherwise, the plants may rot.

According to the level of protection, there are 3 types of shelter:

1. Hilling or burying. This method ensures good wintering for grapes, as long as temperatures do not drop below -15°C. It is advisable to use it to protect frost-resistant varieties.
2. Semi-covering. This method is used in regions with mild and snowy winters. Covering primarily provides root protection. The lower part of the bush is covered with a layer of soil, agrofibre or tarpaulin is placed on top of the vines, and a thin layer of mulch (5 cm) is placed on top.
3. Complete cover. Suitable for harsh winters. The vines, covered with a thick layer of mulch, are further covered with shields or thick material.

Timing of placement under shelter

Cover up grapes for the winter In the temperate zone, this should be done around mid-November. In central Russia (Moscow region), the procedure is usually carried out at the end of November or in early December. Siberian autumn may force you to cover your bushes as early as September.

You shouldn't cover the grapes At above-zero temperatures, especially in rainy autumns, waterlogged vines can crack in the cold. It's best to perform this procedure when the soil is already frozen and will not thaw again.

Grape vines easily tolerate frosts down to -5°C. When laid on the ground, it's beneficial to keep them at -5 to -8°C for 3-5 days—light frosts increase their cold tolerance. If the grape variety isn't frost-hardy, temperatures below -10°C will be critical, and -12°C will kill the plant.

The procedure for covering grapes

The main purpose of winter shelter is to insulate the roots. If the vine freezes, the plant can still be revived, but freezing of the roots will result in the death of the entire bush. Therefore, regardless of the sheltering method, the roots should be covered with a layer of soil and then covered with at least 5 cm of mulch.

Methods of laying vines

Before cover grapes for the winterThe vine should be removed from its support and laid on the ground. In regions with mild, snowy winters and no risk of thaws, you can lay the branches on the ground. Otherwise, one of the following options is recommended:

1. Trench. This method is suitable for grapes grown in regions with harsh or snowless winters and in areas exposed to wind. It's ideal for hilling the vines with soil. Dig a 30-cm-deep furrow near the vine and place the tied vines in it. For additional frost protection, the shoots can be wrapped in burlap.
2. Laying. This method is recommended if the soil may thaw during winter thaws, as well as when mulching with materials prone to dampness. The vines should be laid on a layer of boards, logs, spruce branches, and tree branches.

Types of shelter

Once vines are laid on the ground, they should be placed under an insulating cover. There are two principles for covering grapes:

1. Moist. The vines are covered with mulch—straw, spruce branches, or soil. This method is useful if there is a lot of snow in the winter or significant temperature fluctuations. It is commonly used in regions middle zone.
2. Dry. The grapes are covered with shields or waterproof materials, and a layer of mulch is placed on top. This protects the grapes from severe frosts and wind. This method is used in northern regions where there is no risk of thaws in winter.

Covering young grapes

To cover annual bushes and seedlings, a special technology is required:

1. Annual grapevines are short, so the vines can remain supported. A cone-shaped frame should be installed around the vine. This can be accomplished by driving stakes into the ground and tying them together at the tops, or by using chain-link fencing.
2. The frame should be covered with agrofibre or other material. If the covering is not breathable, leave a gap for ventilation.
3. The space between the cover and the bush should be filled with loose mulch - leaves, straw or spruce branches.

Force majeure

If the gardener was late installing the cover, but the frost was followed by snowfall, there's a chance the plant wasn't severely damaged. In this case, it's necessary to cover the bush with a half-meter layer of snow.

If the temperature drops sharply and snow settles on damp ground, the vine should be raised above ground level, covered with spruce branches or boards, and wrapped in agrofibre. A layer of snow should be piled on top.

If a thaw occurs, cover the vines as planned. If the snow remains until spring, the grapes can safely overwinter under its protection.

https://youtu.be/pyPBQmFVXas

Covering materials

The choice of covering material depends on the typical temperature and precipitation. Important characteristics of the material include:

• density;
• waterproofness;
• air permeability.

Hilling with soil

To protect the bush by creating a mound of earth, use loose, preferably sandy loam soil. Clayey soil traps moisture around the vines, which, when frozen, damages the wood. In the spring, heavy soil warms up slowly, making it impossible to remove the cover in time.

The soil for hilling must be dry and should be prepared in advance. Soil is often taken from between the rows, but this is unsafe if the grapevine is old and tall—the roots that reach this area may freeze.

Before hilling, the vines should be placed in a trench. If severe frosts are expected, a layer of fallen leaves or straw should be placed in the soil. Each layer should be 15 cm thick; the number of layers depends on the required thermal insulation, but the top layer should be soil. The total thickness of the covering layer can range from 15 to 50 cm. The diameter of the mound should correspond to the size of the root system; the minimum is 30 cm (for one-year-old grapes).

Mulch

For winter cover, mulch should be light and loose. In all cases, it's preferable to place the vines on a mat; otherwise, each material has its own installation requirements:

1. Pine branches. The best option for grapes is spruce branches, which allow air circulation and trap snow. The substances contained in pine or spruce branches repel rodents and prevent the development of fungi and mold under cover. The layer should be about 30-40 cm thick.
2. Straw. It's recommended to apply it in two layers as frosts intensify. A 40 cm layer is required. Secure the straw on top with snow or a spunbond cover, otherwise the wind will blow it away. Reed can be used as a substitute for straw.
3. Tree leaves. The material should be dry, but fallen leaves should be dried immediately after collection, not before stacking. The mulching method is similar to covering with straw.
4. Sawdust. It has excellent thermal insulation properties, but it easily absorbs moisture and retains moisture for a long time, so it can only be used in a dry method. Several layers of film should be placed under the vine, and after mulching, slate or wood shields should be installed above the bush.

Snow protection

There's no need to add any additional layer between the bush and the snow. If there's enough snow and there's no risk of thaw, you can place it directly on the branches, in a 40-50 cm layer.

The snowdrift above the bush should be lightly compacted to prevent it from being blown away by the wind. It is recommended to lay the vines on a mat beneath this "mulch."

Slate or plywood

The materials are used as shields in the dry shelter method. In this case soil under the vine The vines should be lined with plastic film and covered with a layer of leaves or straw. Slate or plywood sheets should be installed over the vines to form a pitched roof. The joints between the sheets should be covered with a waterproof material (film, roofing felt), and then covered with soil to secure them. The sheets can be insulated by placing burlap, paper, or cardboard boxes on top, which should then be covered with layers of leaves and soil.

Artificial materials

In rare cases, synthetic covering materials can be used as a stand-alone protection for grapes; more often, they are combined with mulch, earthen mounds, or shields.

1. Agrofibre. This material can only be used without additional insulation in southern regions. In this case, it's permissible to cover or wrap the vines without removing them from the trellises. Colder winters or alternating thaws and drops in temperature will require a thicker layer of mulch. Spunbond is permeable to moisture, so a mat should be placed under the vines.
2. Roofing felt. Suitable for covering grape vines growing in warm but snowless winters. The vines should be placed in grooves and covered with roofing felt. The material is impermeable to water and air, leaving gaps for ventilation. If frosts intensify without snow, a layer of mulch should be placed over the roofing felt.
3. Film. This material is used when it's important to prevent precipitation from falling on the vines. However, film won't protect against frost; it can only be used as an additional covering, for example, along with mulch. The covering is made like a greenhouse—the material should be stretched over arches installed above the vine. The edges of the film should be covered with soil, leaving a gap on one side for air circulation. It's important to have a gap of air between the film and the vines; areas touching the thin covering will freeze.
4. Polymer film. One of the serious drawbacks of covering with film is the formation of condensation on the inner surface of the material. This can lead to the bushes being susceptible to fungal and rot damage. However, if you use a high-density, reflective polymer film, moisture problems will be eliminated.

Protecting the shelter from fungi and rodents

Some covering materials promote the development of diseases or colonies of pests, so you need to take care to protect the grapes.

1. Rats or mice can get under the shelter and chew the vines, so poisoned bait should be left near the bush. Mulching with straw, sawdust, and dry leaves encourages rodent infestation.
2. It's important that the leaves used for mulching shrubs are not infected with fungus. Only take material from healthy trees.

3. Using film as a covering material increases the risk of fungal growth on grapes. Fungal spores may remain on the film from the previous year, so when reusing the cover, treat it with copper sulfate (4%) and leave it to dry without rinsing.
4. Dried bunches of insect-repellent herbs, such as tansy, wormwood, marigold, and calendula, can be placed around the bush.

Autumn weather can be unpredictable, so it's important to monitor temperatures to ensure timely sheltering of vines. It's crucial to select the appropriate type of protection and materials for the climate to ensure grapes are not damaged by cold, heat, humidity, or fungus.