Ways to save plants from them
Frosts are such a common and frequent occurrence in our country that protecting plants from them is one of the most important activities for gardeners. And frosts, alas, cause us a lot of trouble, because they happen here in the Urals both in May and June (I think many remember the frost on the night of June 17, which was observed several years ago). Frosts are common in late spring and early summer in other regions.
In addition, unfortunately, our summer is so short that we naturally have to sow and plant various crops long before mid-June, otherwise we won’t get a harvest. Trees and shrubs don’t “ask” us at all and bloom according to their own laws and rules. And as a result, both they and heat-loving plants in greenhouses and hotbeds, and cold-resistant plants in the open ground, are every year exposed to the destructive effects of low temperatures. Very often, frosts come when trees and shrubs are in bloom, potatoes are already pleasing to the eye with green tops, strawberries are opening flower buds, and tomatoes and cucumbers are already planted in greenhouses. In general, everything is pleasing to the eye. And it is in our power to help plants endure an unfavorable period.
True, today the arsenal of tools and techniques used for this leaves much to be desired. Although, perhaps, in the near future everything will fundamentally change. The basis for this may be the fact that quite recently scientists in the USA synthesized a substance that fish living in the Arctic and Antarctic secrete to protect themselves from the cold. Until recently, researchers were unable to make an exact copy of this unique natural antifreeze. And finally, a miracle came true: employees of the New York State University found the desired formula. The resulting chemical can be used in everyday life: for example, it can be sprayed on plants to protect them from frost. So, apparently, in the near future we will be spraying against frost, as well as against pests and diseases.
Signs of approaching frosts, as a rule, are an increase in atmospheric pressure, an intense drop in temperature in the evening, a cloudless sky and complete calm. During freezing, the temperature on the soil surface drops below 0°C, while the air temperature at a height of 1-2 m may not always be negative.
The intensity and frequency of frosts are greatly influenced by the nature of the relief, soil moisture, its color, the presence or absence of vegetation, etc. From this point of view, the most frost-hazardous are low-lying landforms. In elevated areas and in the valleys of large rivers, near reservoirs, and large populated areas, on the contrary, frosts are weaker and less frequent. In addition, the earlier spring comes, the earlier trees and shrubs bloom and the more likely they are to be damaged by frost.
Protection of trees and shrubs
When expecting frost, you should keep in mind that in general, berry bushes are more susceptible to frost than trees, because The temperature at the soil surface is usually lower than at the crown level. Therefore, with minor frosts, it also happens that flowering gooseberries lose part or all of their bountiful harvest, while apple trees lose virtually nothing. Moreover, currant and gooseberry ovaries are more sensitive to low temperatures than even opened flowers.
Unfortunately, there are very few options for protecting trees and shrubs today.
Let's talk about smoking
The most famous and widespread method of combating frost is smoking, which was used even before our era by the Romans to protect vineyards, as well as by the ancient inhabitants of Peru to save their corn crops. In the classic version, the smoke pile consists of dry branches and straw, and is covered on top with a thick layer of damp material (for example, grass, moss, sawdust, turf, earth or peat), which enhances the smoke. At the same time, on one side of the heap a place is left for ignition. The pile itself should reach a width and height of up to 1 meter. Of course, several such heaps should be prepared on the site. The smoke screen should evenly envelop the entire area. It is better to smoke closer to dawn and within two hours after sunrise until the air temperature rises above zero. When there is calm or light wind, the temperature from burning smoke piles usually increases by only 0.8-1°C.
A slightly greater effect (up to 1-1.5°C) is achieved when using smoke bombs. However, in windy conditions and in rugged terrain, smoking is absolutely ineffective.
And, to be honest, after having suffered several times with organizing this process, I abandoned it as ineffective. The main reason for the ineffectiveness of smoke in our conditions is that, on the one hand, we have wind, despite frosts, very often. On the other hand, frosts in the Urals are such a frequent and regular occurrence that the preparation of materials for smoke heaps can be done throughout the entire season (there is no time for anything else).
Artificial fog
And in America (naturally, in areas exposed to frost), farms also widely use artificial protection of plants from low temperatures. The greatest effect is obtained from artificial fogging, for which appropriate installations are used. In our case, the role of such a mini-installation can be played by an ordinary sprayer, but its power is only enough to maintain fog in a small greenhouse, but nothing more. 
Protection of bushes and low trees(in our conditions, as a rule, cherries and plums)
To prevent the buds or already opened flowers on the bushes from freezing, you can stick four large pegs around each of them and wrap this frame with thick plastic film or, even better, covering material. The covering material can be directly thrown over flowering shrubs and fairly short trees. In any case, after constructing such a mini-shelter, you will need to carefully strengthen the film or covering material with ropes, wrapping them around the structure and tying them well. Do not leave holes in the shelter at the top or bottom. It is usually more convenient to throw the same film or covering material on top, and then sprinkle earth on the bottom, or press down with stones, or, when covering small trees, tie it around the trunk at the bottom.
Especially about the outflow of cold air
You should never build a continuous hedge of bushes at the foot of the slope on which the garden is laid out. Cold air, flowing down, will be retained by it, and a frost-killing basin created by you yourself will appear, deadly in the spring for flowers and buds.
Protecting potted plants
The underground parts of plants in plastic, ceramic pots and seedling containers, which for some reason cannot be brought into the house in cold weather, will not die if the pots are packed in large containers (for example, tanks) filled with straw or sawdust. It is better, of course, if these tanks are installed during cold weather in the greenhouse, or at least tightly closed on all sides with covering material.
Protection of vegetable plants in open ground and strawberries
Hilling up "with your head" and a straw blanket for potatoes. Frosts on the soil are dangerous for many heat-loving plants. You can provide protection by covering the soil around the plants with a thick layer of straw or hay. An even better option is when an additional layer of film or covering material is applied on top (on top of straw, hay). This technique is especially convenient for ordinary potatoes (it’s not for nothing that in the 18th century, in the northern regions of the Russian Empire, monks successfully grew the so-called “straw potatoes”).
Although, to organize the protection of newly emerged potato seedlings, you can simply cover them with earth “head over heels”. It’s more effective to hill up first and then cover with a layer of hay. And then no frosts are scary. Hilling up in itself is a fairly temporary measure, because almost the next day the potato shoots will begin to “crawl” out of the shelter, and frosts are not limited to one night during the season.
Protection of sufficiently cold-resistant crops
In this case, we are talking about carrots and onions sown (planted) in open ground back in April (early May). Of course, carrots are a cold-resistant plant, but also to a certain extent. And it will develop poorly in very cold weather, and this will subsequently affect the harvest. So it’s not a sin to take care of her. And it’s not even worth talking about onions, because if they get frozen, they have every chance of going to waste.
As for young and recently emerged carrot shoots, you can’t think of anything better than a thin covering material. You close it, and “your head won’t hurt” about frosts, watering (of course, you need to water, but much less often) and loosening.
And it is enough to cover onions planted on May 1-5 before the emergence of shoots with film. It is better, despite the inevitable frosts, to plant onions in our conditions at such an early date, because... it will be less negatively affected by the prolonged rains that are so frequent in August. In the event of frosts, which are almost annual at this time, the film will reliably protect the planted onions. After the shoots emerge, the film will have to be removed and be sure to be replaced with a thick covering material. In this case, if there are frosts down to -5...-7°C, you don’t have to worry: nothing bad will happen to your onions. And he will be reliably protected from the ubiquitous onion fly.
Strawberry protection
First of all, in our conditions it is better not to allow strawberries to start growing too early, because lowering the temperature to -1...-1.5°C can lead to the death of its flowers and ovaries. Therefore, there is no need to rush into processing it. If frosts are likely already at the stage of formation of peduncles, then nothing can be done - you will have to take urgent measures. The simplest thing is to throw covering material over the strawberry beds. The only thing you need to remember is that pollination of flowering strawberry bushes will not occur under the covering material, so it should only be used for short-term protection from frost.
How and with what to heat greenhouses and greenhouses?
A well-known fact today is that the yield of vegetables in Russian greenhouses and hotbeds is half as much as in Holland, Denmark and Finland, which have the most developed greenhouse industry in the world. There are several reasons for this state of affairs. This includes ineffective agricultural technology, the use of not the most promising hybrids, the lack of a reliable soil heating system, low-quality films, etc. and so on.
Separately about soil heating
As for heating, in principle there are three methods of heating protected soil - solar, technical and biological.
1. Solar - the most common and cheapest. But on cloudy and rainy days, the temperature under the film may be below the optimal limit. I'm not even talking about night frosts. In other words, it is very difficult to manage only with solar heating in the conditions of the Urals. You can, of course, turn on temporary additional heating during frosts, for example, using electric heaters. But this option is not particularly reliable. Firstly, it requires a constant presence on the site, which is not always possible. Secondly, there are also very unexpected frosts, which are unknown in advance. Thirdly, heating using electrical appliances requires constant monitoring, which is also very problematic. Therefore, after using this option for several years, I was forced to abandon it.
2. Technical heating. Used in small greenhouses. In this case, stove, gas or water heating is used. In our country, as a rule, unlike the West, individual greenhouses use stove heating. In general, technical heating through stove heating, as one of the options for creating the optimal temperature in greenhouses, has its pros and cons. On the one hand, this makes it possible to win about a month by getting greens and early white cabbage. On the other hand, this heating method requires a constant presence on the site and almost constant firing of the stove, which in the end will be quite expensive both in terms of the firewood used and in terms of time spent. More efficient, of course, are gas and water heating options.
3. Biological heating. It is based on the decomposition of organic materials, due to which heat is released in an amount that is sufficient for the entire growing season. In addition, the air in greenhouses is enriched with carbon dioxide. Horse manure is considered a classic biofuel. Compared to horse manure, all other types of manure are colder and heavier, warm up more slowly, and their combustion temperature is lower. When using pig and cow manure, it is necessary to mix in straw and sawdust, which ensures loose soil. Leaves, crushed bark, hay, etc., mixed with manure, are also suitable as biofuels. From my point of view, the optimal option is when fresh manure is mixed with sawdust and some kind of organic matter (I, as a rule, use leaves), although in Rus' monks used only straw, well-sprinkled with mullein, to fill greenhouses. 
Water - don't water...
The issue of watering various crops during frosts is quite controversial. We can definitely say that watering heat-loving crops (especially melons) before frost is very dangerous - they can survive the frost, but get sick, which is also not good.
As for other crops, during significant frosts (below -2°C) it is completely pointless to water the ground under the plants: on the contrary, it will only cause harm. But fine-drop spraying in such cases is a fairly effective, although troublesome, measure. For this purpose, sprayers are used, which are usually used to combat pests and diseases. Spray at dawn, starting at four o'clock in the morning, and in low places - even earlier, thereby creating a fog effect. After 15 minutes, spraying is repeated - and so on until the temperature rises.
If frosts are light (up to -2°C), then moist soil under cold-resistant crops can help them survive the cold night. Damage will be significantly less due to the evaporation of soil moisture during exposure to low temperatures. But other options are still more reliable, for example, the same covering material, than experiments with water, when you don’t know exactly what kind of frost will “make you happy.”
After frost, you should never water frozen plants with warm water (as is sometimes recommended). This “treatment” could easily kill them. It is better to wrap the shoots with covering material: perhaps slow thawing will allow them to partially recover.
Svetlana Shlyakhtina
The probability of spring return frosts exists until mid-June. When you have several flowering shrubs, you can quickly cover them with lutrasil, bags, straw, shields on stands, mats, etc.
If the cold threatens the plantation strawberries or orchard, completely different measures are required.
The greatest threat from frost poses to crops that grow in swampy and low-lying areas, on wet and peaty soils. Short-term drops in temperature are dangerous for newly planted young plants that have not yet had time to take root. The worst thing is if frosts occur during flowering fruit trees And berry bushes. If the air temperature remains at a critical level for 4 hours, then this will be enough for the generative organs of plants to receive partial or complete damage.
You can predict the likelihood of night frost by the following phenomena:
- during sunset: clear sky and +5-6°C on the thermometer;
- in the absence of wind and clouds, by 21:00 the air temperature drops below 2°C;
- weak wind, cloudy sky, atmospheric pressure increases and temperature decreases (0°C);
- if the barometer needle rises, but the cloudiness decreases.
Preventive measures to protect the garden from the effects of spring frosts:
- It is necessary to plant fruit trees and berry bushes, especially early-flowering varieties, on elevated points of the site. Otherwise, cold air descending into the lowlands can cause crop loss and freezing of young shoots that have already grown.
- Choose varieties that bloom late, because... Compared to flowers and ovaries, buds are the most resistant to frost.
- Carry out moisture-recharging irrigation in both autumn and spring; it increases air humidity and softens the negative effects of sub-zero temperatures.
- Use products for spraying plantings that shift flowering to a later date.
Protecting the orchard from night frosts
The probability of frost is high in the year when spring comes too early. Bright sunlight and rapid heat encourage trees and shrubs to grow and bloom prematurely. Moreover, shrubs are more susceptible to night frosts than trees. This happens because the temperature on the ground is much lower than in the air.
To save the buds and the flowers have already opened, drive 4 pegs around a bush or low tree, wrap them in plastic film, lutrasil or burlap and tie them with a rope. Sprinkle the lower edges of the covering material with earth or press down with stones.
For heat-loving crops, make a box of suitable size from boards. Fill the space between the plant and the walls of the box with dry leaves, sawdust or straw. Cover the top with film, lutrasil or other material.
Smoking
To protect flowering trees, shrubs and vineyards from night frosts, you can use a method such as smoking.
Place several stacks of straw, hay or dry branches around the area. Cover them with a good layer of damp grass, sawdust, turf soil, moss, and peat. Leave a dry place for lighting. The size of the stack should be approximately 1x1x1 m. Carry out smoking before dawn for two hours, until the air temperature becomes positive.
Artificial fog
The method is often used on farms using special installations. In a small area create a fog effect can be done using a conventional sprayer. This technique promotes the formation of an ice shell, the temperature under which is higher than outside. This helps preserve the color. Due to the evaporation of water, the ambient temperature rises by 3°C. Start work on creating artificial fog at dawn, and in the lowlands a couple of hours earlier. Spraying is carried out in several stages until the temperature becomes above zero.
During spring and late spring frosts, almost all garden crops can be vulnerable. Only honeysuckle flowers can withstand temperatures down to minus 7 degrees, and raspberries are not damaged, since they bloom later, when the danger has passed. Other crops can “react” to a temperature of minus 1.
The extent of damage depends not only on the level of low temperatures, but also on their duration. Stronger, but short-lived frosts (lasting up to an hour) are less harmful than weaker ones, but lasting several hours. The most dangerous hours are in the morning, when the sun rises. Frozen plant cells begin to evaporate moisture under the influence of sunlight, they become dehydrated and die. For the same reason (drying out), wind immediately after freezing is also dangerous.
Please take note of this fact. Frosts were stronger over soil covered with loose mulch or growing grass than over open surfaces.
Ovaries caught by frost can produce a harvest, although the fruits will have an unmarketable appearance.
All these natural factors accompanying frosts, cause some controversy and controversy in the horticultural literature. It is believed, for example, that the ovaries of apple and pear trees are more vulnerable than the flowers. But facts show that this is not always true.
Here's an example. In the last five years alone, there have been late spring frosts three times: in 1992, 1993 and 1995. Let’s skip the first two years and remember the year 1995. The heat then “arrived” on April 10, and from April 20 the temperature settled at plus 25 degrees. All this caused a more accelerated development of phenophases than in normal years - the first pear flowers bloomed already at the end of April. But the cooling that began later delayed the mass flowering and made it extended. The first night frost of about minus 1 degree was on May 1, the second was on May 3, with a temperature of minus 4-5 degrees. It caused damage only to single blossoming pear flowers, and mass flowering of apple and pear trees began after May 10, when there were no more frosts.
First of all, I note that apple and pear flowers turned out to be less resistant to frost than ovaries. This can be seen from the following facts: late-blooming apple tree varieties lost their flowers completely in 1992 and 1993, and early-blooming pear flowers died in 1995.
At the same time, the pear practically did not reduce the yield - frosts helped to “thin out” the fruit set. Pear ovaries turned out to be more stable than apple ovaries. This is probably due to their size: during the frost period they were more than a centimeter in diameter, while the apple tree was much smaller. Only the earliest flowering varieties (including the varieties Cloz, Melba, Quinti, Julired) had ovaries of 0.8-1 centimeters at the time of frost, and they retained 70 percent of their usual yield.
Note: Due to their resistance to low temperatures in winter, these varieties are not winter-hardy in the conditions of the Moscow region. This proves the absence of any connection between winter hardiness as such and resistance to late spring frosts. This was especially evident in crops - almost all varieties of pear, which are considered less winter-hardy, retained a good harvest in years with late spring frosts. And later, the flowering apple tree suffered greatly, including its most winter-hardy varieties.
Another interesting observation. After a 6-degree frost in 1993, the pear ovaries froze through and looked like glass. Gradually they thawed, but this still affected the subsequent development of the fruit. In some varieties (Lada, Chizhovskaya, etc.), rings of rustiness appeared on the surface of the fruit. They, of course, somewhat reduced the presentation, but did not affect either the size of the fruit or their taste.
In another group of varieties (Naryadnaya Efimova, Duchess Letniy, Gerasimovka, Ilyinka, Moskovskaya, etc.), the fruits at the ripening period had the “necessary” appearance, size and taste, but were without seeds. There was also no granulation around the seed chambers, typical of some varieties.
You see what is happening: the varieties differ in winter hardiness, flowering and ripening periods, but their reaction to late spring frosts was the same.
For many varieties, here’s something else that was noticeable: A clear layering of damage along the height of the tree appeared. In the upper and middle parts there were fruits that were usual for the variety, but in the lower part (up to about 1.2 meters from the ground) there were either no fruits at all, or they were very small, deformed, and asymmetrical. Moreover, they neither fell nor developed. Because of this, the overall pear yield has decreased. Consider this point when forming trees with a low crown.
Blooming spring gardenWith the arrival of spring, there is still a high probability of frost, but the trees in the garden have already begun to actively develop and bloom. There are several proven ways to protect plants from frost, which will help keep the garden healthy and reap a good harvest.
With a significant and sharp cold snap, from 10 degrees Celsius during the day to 5 degrees below zero at night, not only the flowers die, but also the young ovaries on fruit trees. It is very important to predict in time whether there will be frost and take the necessary safety measures.
The approach of a sharp cold snap can be judged by high atmospheric pressure, calmness, clear weather and a decrease in air temperature. The most dangerous period for plants occurs in the first hours of dawn.
Gardeners can adopt the following frost resistance techniques:
- smoke from burning weeds or smoke bombs;
- artificial fog using a special sprayer;
- film shelter and a candle burning under it;
- synthetic fiber or other covering material.
Smoke from fruit trees
Combustible material (straw, hay, dry leaves) is piled up on different sides of the site, covered with moss, sawdust or damp grass on top, and set on fire. The top damp layer retards combustion and produces a lot of smoke.
This allows you to keep the temperature above zero by 1-2 degrees and protects flowering trees from the cold. But, unfortunately, this method is effective only in complete calm, otherwise the smoke screen will be blown to the side.
Garden smoke bombs for fumigating fruit trees
When the checkers burn, the flowers and ovary are covered with a thin layer of paraffin, which resists frostbite, and when the air temperature rises, it simply evaporates. But it is necessary to take into account the presence of wind, and promptly move the source of smoke in the right direction.
Artificial fog for large areas
In world practice, special installations are widely used to create artificial fog, which envelops fruit trees and reliably protects them from the cold. But this method is designed for large areas and is suitable for farms or gardens with large areas, since special equipment for spraying and equipment for transporting it are required.
Film shelter
When there is a threat of frost, trees are covered with plastic film, the ends of which must be fixed under the crown, closer to the trunk. The result is a dome-shaped structure, and an open candlestick with a lit candle is suspended inside the crown. The heat from a candle in such a shelter is quite enough to maintain a positive temperature.
If the candle is not used, the film is fixed under the crown, tightly clasping the trunk. When the air temperature rises, the shelter must be removed immediately.
Synthetic fiber tree cover
Very often, gardeners use agrofibre to protect a blooming garden. A piece of covering material is thrown over the crown and tightly fixed to the trunk.
If there is an assumption that the frost will last for several days, then you don’t have to remove it at all during this time. Today this is the most common method, since it is less labor-intensive and does not require constant presence in the garden.
Frosts in spring are a common occurrence. It consists of a temporary decrease in air temperature to negative values in a specific area. Frosts pose a direct threat to the flowers and ovaries of fruit trees. The flowers and fruit ovaries of most fruit trees are very delicate; they are damaged at -2°C, and the ovaries are already damaged at -1°C. Protecting the garden from frost is a problem for gardeners, especially with the arrival of early spring.
Types of spring frosts
There are several types of spring frosts. These are radiation, adventive, and mixed frosts.
Radiation freezes occur on windless and cloudless nights, they arise due to the rapid radiation of heat from the earth's surface into open space. The occurrence of such frosts is impossible during cloudiness, since cloudiness screens out heat. Radiation freezes are usually short-lived and often repeated.
Adventative frosts are more dangerous. They arise due to the invasion of cold air masses from the Arctic regions. The weather service usually warns about such frosts. Adventitious frosts last longer.
Mixed frosts in the middle zone they arise during the arrival of cold Arctic anticyclones. Cold air masses are combined with a lack of wind and cloudiness.
Ways for gardeners to combat frost
All work to prevent the negative consequences of spring frosts is divided into preventive and immediate.
Prevention of frost protection
Preventive work consists of selecting frost-resistant varieties. Also in the proper placement of garden plantings, taking into account the microclimate and topography of the site. Very often, trees suffer from frost if they grow in lowlands or, conversely, in too open places and suffer from excessive moisture or excessive dryness of the soil.
Preventive methods include keeping snow on the site and whitewashing fruit trees with gypsum milk or a special polymer. Snow retention and whitewashing do not allow garden trees to warm up for some time. Thus, the flowering phase of garden plants is postponed to a later date.
Smoke barriers
Forecasters usually begin to report the likelihood of frost. But an experienced gardener knows that if, after a hot day, by 20 o’clock the temperature drops sharply, and there is not a cloud in the sky, there is no wind, then frost is likely. Wind, cloudy night skies, and morning dew indicate that there is no likelihood of a cold snap.
The signal to begin immediate work is when the air temperature drops to +2°C. Smoke barriers are most often used to directly protect plants. To create a smoke barrier in the garden, you need to prepare in advance several piles of last year's leaves, straw, and organic debris. The combustion of such heaps produces a large amount of warm smoke and water vapor. Smoking will be effective in frosts down to -2°C.
How to make a smoke pile
They lay a stake, cover it with straw, wood chips, brushwood, after which they add organic residues (manure, leaves) and cover the whole pile with earth. Light the pile with a torch soaked in oil or kerosene.
The pile should burn slowly for 5 – 6 hours. For every 1 - 2 trees, make 1 pile.
The lowest temperatures during frosts occur before sunrise.
Saving berries and vegetables
To protect small berry plants and flowering seedlings, you can create shelters from newspapers and polymer material.
Lightweight lutrasil shelters and films retain heat coming from the soil around plants. This technique, like smoking, is well complemented by sprinkling: wet soil gives off more heat.