How to vernalize potatoes before planting


Vernalization is a special technique for preparing seed. Seeds are exposed to low temperatures, about 2 to 4 degrees Celsius. For potatoes, the concept of "vernalization" implies the germination of tubers for early harvest.

Tuber preparation

To get a good harvest of potatoes, it is very important to prepare high-quality seed material. For planting selected tubers of medium size, weighing from 70 to 100 grams. You must carefully examine each tuber, any spots, holes can be signs of infection with infectious diseases or harmful insects.

If potatoes sprouted during storage, you must inspect the sprouts. Healthy sprouts are pink, greenish or purple in color. They are smooth, thick, elastic.

A warning! If the sprouts are black, then they are damaged by fungal diseases or frozen. For planting such tubers are unsuitable.

Often, when examining tubers, one can notice potato tubers with thin, filiform sprouts. The causes of the appearance of such germs are many, but the main one is the defeat by viral infections. To get a harvest from such a potato is impossible. If more than half of the seeds of potatoes have such sprouts, it is necessary to replace the planting material completely.

Important! Spiders of viral and fungal diseases often become sucking insects - aphid, flea, ticks. Reproduction of such insects occurs, as a rule, in thickets of weeds and wild-growing herbs.

If the sprouts appeared on the potatoes, and before planting at least another month, they are preferably broken off. This will give the opportunity to wake up sleeping eyes at the potato. Planting too long shoots is undesirable, they are very easy to break off, they will need more time to adapt to changing temperatures.

The timing of vernalization

Vernalization of potatoes before planting begins 30 - 40 days before planting in the ground. In early varieties of potato sprouts appear a few days earlier than the late ones.

To determine the time of the beginning of the vernalization of potatoes, it is necessary to count 40 days from the approximate time of landing in the ground. If you start early vernalization, the sprouts will be too long, they are easy to injure during planting.

Planting potato tubers in the ground begin when the soil warms to 6 - 8 degrees. Depending on the method of planting, the temperature is measured at a depth of 20-40 cm. It is necessary to prepare shelters for potatoes in case of return frost.

Ways of vernalization

There are three ways of vernalization - dry, wet and combined. For vernalization of potatoes at home, any of them will do.

Dry way

With this method of vernalization, the potatoes are left dry, occasionally sprinkling it. The main advantage of this method is that potatoes are less affected by fungal diseases.

Among those who like to grow potatoes, a dispute often arises as to how best to vernalize planting material - in the light or in the dark. Proponents of the first method argue their case by the fact that under the action of sunlight in tubers solanine is formed - a natural insecticide and fungicide. Potato tubers with solanine are less affected by fungal diseases and harmful insects.

Proponents of the second method motivate their choice by the fact that under natural conditions, the development of potatoes occurs underground and human intervention in natural mechanisms can only worsen the yield.

There are several options for placing potato tubers for vernalization:

  • Spread out on the floor in one - two layers;
  • Place on racks;
  • Hang on the wall or ceiling in transparent bags;
  • Strung on a wire or twine and hang.

The disadvantage of the first option - you need a lot of free space in a bright, heated room, which is often difficult to ensure. If there is such a room, the floor is covered with an oilcloth or paper. Tubers of potatoes laid out in one or two layers, once a day, sprinkling with a spray bottle. It is necessary to turn the tubers every 2 - 3 days.

Important! In a private house there may be cold floors. Air temperature must be measured on the floor surface.

For the second way to vernalize the tubers will need shelving. The distance between the shelves should be at least 30 cm so as not to obscure the germinated tubers. This option saves space in the room, but requires the cost of purchasing racks or materials for their construction.

The option with transparent bags is the most economical. Plastic bags are inexpensive, you can place them anywhere. Often, glazed balconies are used for these purposes, nails are carved into the walls, and the tubers are jarnized on them. You must ensure that the temperature of the air on the balcony does not fall below 5 degrees Celsius.

Important! Be sure to make holes in the packages for ventilation. Potatoes during germination releases moisture. Condensation on the surface of the bags can harm tubers.

The fourth method also saves space, strung potatoes can be placed in the room, on the balcony, a warm veranda. If the weather is warm outside, potato garlands can be brought outside.

Prepared by dry vernalization potatoes, has several sprouts up to 3 cm in size. White points are visible on sprouts - the beginnings of roots.

Wet method

This method involves placing potatoes in a humid environment. For vernalization most often used:

  • Sand;
  • Sawdust;
  • Peat;
  • Perlite.

Sand is the least suitable option; it conducts air poorly. Potatoes placed in the sand are often affected by fungal infections or rotting.

Sawdust conducts air well, but is often unevenly moistened. May contain pathogens of infectious diseases and the larvae of harmful insects. It is undesirable to use oak sawdust.

Peat does not contain pathogens of fungal infections, potatoes sprout well in it. It also contains nutrients that can provide additional nutrition to the tubers. The only minus of peat is the danger of waterlogging. Often has a high acidity, for the germination of tubers, it is desirable to add ash.

Potatoes grown in perlite are not susceptible to fungal diseases. Perlite perfectly absorbs water, it is difficult to re-moisten it.

Before laying the tubers for vernalization, the bottom of the box where they will be, covered with paper or plastic wrap, pour a small layer of wet substrate. Spread the potatoes and substrate in layers until the box is filled.

The boxes are transferred to a room with a temperature of about 15 degrees. It is necessary to monitor the moisture content of the substrate and the condition of the tubers in order to prevent drying.

A tuber ready for planting has a sprout of 3–5 cm in size, numerous roots. Do not allow tubers to dry out during planting. Before planting potatoes, it is desirable to treat long-lasting insecticides.

Combined method

The essence of this method is that the potatoes are first vernalized in the light, and then placed in a moist substrate for rearing.

Selected for planting potatoes are placed in a bright place, the temperature of which does not exceed 10 degrees Celsius. Leave for 2 weeks. It is necessary to turn the tubers daily and spray them.

When the potato sprouts, it is placed in boxes with a wet substrate before the formation of the roots. This process takes an average of 3 weeks. Potatoes of early varieties form roots more quickly.

Jarovized potatoes are planted immediately from the box, where they were germinated to avoid drying of the roots.

Tuber processing

To prevent the occurrence of problems with planting material, the tubers must be processed before laying on the vernalization.

For the treatment of tubers use the following types of chemicals:

  • Fungicides;
  • Growth stimulants;
  • Nutrients;
  • Insecticides;
  • Disinfectants.

Fungicides must be processed if the potatoes are grown in the rainy season or bought on the market. Wet weather contributes to the spread of fungal spores. Often in appearance tuber imperceptibly that it is affected by a fungal infection, the first signs of damage appear during the growing season.

Purchased from an unknown producer, seed potatoes can contain many pathogens of infectious diseases, which not only affect the crop of potatoes, but can also infect the soil.

In this case, before laying on the vernalization, the potatoes are thoroughly washed with disinfectants, trying not to damage the peel. Wash the field of potatoes soaked or sprayed with fungicides according to the instructions.

Growth stimulants can reduce the time of vernalization and potato cultivation by 1 - 2 weeks. As a rule, they contain identical natural phytohormones, which contribute to the rapid development and good yields.

Processing potassium preparations before vernalization allows you to fill the nutrient deficiency in the tuber. Potatoes develop faster, have a good resistance to stress.

It is very important to treat the tubers from harmful insects, especially if there were cases of damage by a scoop, wireworm or other pests on neighboring sites. Potato tubers may contain insect larvae.


Narrowing tubers before planting does not require much time and effort. By choosing the appropriate method, you can significantly improve the yield of potatoes, reduce the time of cultivation.