Negative influence cold depends on the range of lower temperatures and the duration of their exposure. Already non-extreme low temperatures adversely affect plants, because:

• inhibit the main physiological processes (photosynthesis, transpiration, water exchange, etc.),
• reduce the energy efficiency of breathing,
• change the functional activity of membranes,
• lead to the predominance of hydrolytic reactions in the metabolism.

Externally, cold damage is accompanied by a loss of turgor by leaves and a change in their color due to the destruction of chlorophyll. The main reason damaging action low positive temperature on heat-loving plants - a violation of the functional activity of membranes due to the transition of saturated fatty acids from a liquid crystal state to a gel. As a result, on the one hand, the permeability of membranes for ions increases, and on the other hand, the activation energy of enzymes associated with the membrane increases. The rate of reactions catalyzed by membrane enzymes decreases faster after a phase transition than the rate of reactions associated with soluble enzymes. All this leads to unfavorable changes in metabolism, a sharp increase in the amount of endogenous toxicants, and, with prolonged exposure to low temperatures, to the death of the plant.

It is found that the action low negative temperatures depends on the state of plants and, in particular, on the hydration of body tissues. Thus, dry seeds can tolerate temperatures as low as -196°C (liquid nitrogen temperature). This shows that the detrimental effect of low temperature is fundamentally different from the effect of high temperature, which causes direct protein coagulation.

The main damaging effect ice formation has an effect on the plant organism. In this case, ice can form as inside the cell and outside the cell. With a rapid decrease in temperature, the formation of ice occurs inside the cell (in the cytoplasm, vacuoles). With a gradual decrease in temperature, ice crystals are formed primarily in the intercellular spaces. The plasmalemma prevents the penetration of ice crystals into the cell. The contents of the cell are in a supercooled state. As a result of the initial formation of ice outside the cells, the water potential in the intercellular space becomes more negative compared to the water potential in the cell. There is a redistribution of water. The balance between the water content in the intercellular spaces and in the cell is achieved due to:

• or the outflow of water from the cell,
• or the formation of intracellular ice.

If the rate of water outflow from the cell corresponds to the rate of temperature decrease, then no intracellular ice is formed. However, the death of the cell and the organism as a whole can occur as a result of the fact that ice crystals formed in the intercellular spaces, drawing water from the cell, cause its dehydration and at the same time exert mechanical pressure on the cytoplasm, damaging cellular structures. This causes a number of consequences:

• loss of turgor
• increase in the concentration of cell sap,
• a sharp decrease in cell volume,
• shift of pH values ​​in an unfavorable direction.

Plant resistance to low temperatures is divided into cold resistance and frost resistance.

Cold tolerance of plants- the ability of heat-loving plants to tolerate low positive temperatures. Protective value under the action of low positive temperatures on heat-loving plants has a number of adaptations. First of all, it is the maintenance membrane stability and ion leakage prevention. Resistant plants are distinguished by a greater proportion of unsaturated fatty acids in the composition of membrane phospholipids. This allows you to maintain the mobility of the membranes and protects against damage. In this regard, the enzymes acetyltransferase and desaturase play an important role. The latter lead to the formation of double bonds in saturated fatty acids.

Adaptive reactions to low positive temperatures are manifested in the ability to maintain metabolism when it decreases. This is achieved by a wider temperature range of enzymes, the synthesis of protective compounds. In resistant plants, the role of the pentose phosphate pathway of respiration increases, the efficiency of the antioxidant system increases, and stress proteins are synthesized. It has been shown that under the action of low positive temperatures, the synthesis of low molecular weight proteins is induced.

To increase cold resistance, pre-sowing soaking of seeds is used. The use of trace elements (Zn, Mn, Cu, B, Mo) is also effective. So, soaking seeds in solutions of boric acid, zinc sulfate or copper sulfate increases the cold resistance of plants.

Frost resistance of plants- the ability of plants to tolerate negative temperatures.

Plant adaptations to negative temperatures . There are two types of adaptations to the action of negative temperatures:

• avoidance of the damaging effect of the factor (passive adaptation),
• increased survival (active adaptation).

Escape from the damaging effect of low temperatures is achieved primarily due to a short ontogenesis - this care in time. In annual plants life cycle ends before freezing temperatures. These plants have time to give seeds before the onset of autumn cold weather.

Most perennials lose their above-ground organs and overwinter in the form of bulbs, tubers or rhizomes, well protected from frost by a layer of soil and snow - this care in space from damaging effects of low temperatures.

hardening- this is a reversible physiological adaptation to adverse effects, occurring under the influence of certain external conditions, refers to active adaptation. The physiological nature of the process of hardening to negative temperatures was revealed thanks to the works of I.I. Tumanov and his schools.

As a result of the hardening process, the frost resistance of the body increases sharply. Not all plant organisms have the ability to harden, it depends on the type of plant, its origin. Plants of southern origin are not capable of hardening. In plants of northern latitudes, the process of hardening is confined only to certain stages of development.

Hardening of plants takes place in two phases:

First phase hardening takes place in the light at slightly lower positive temperatures (about 10 ° C during the day, about 2 ° C at night) and moderate humidity. In this phase, a further slowdown continues, and even a complete stop of growth processes.

Of particular importance in the development of plant resistance to frost in this phase is the accumulation of cryoprotective substances that perform a protective function: sucrose, monosaccharides, soluble proteins, etc. Accumulating in cells, sugars increase the concentration of cell sap and reduce water potential. The higher the concentration of the solution, the lower its freezing point, so the accumulation of sugars stabilizes cellular structures, in particular chloroplasts, so that they continue to function.

Second phase hardening proceeds with a further decrease in temperature (about 0 ° C) and does not require light. In this regard, for herbaceous plants it can also run under the snow. In this phase, there is an outflow of water from the cells, as well as a restructuring of the protoplast structure. The neoformation of specific, dehydration-resistant proteins continues. Of great importance is the change in the intermolecular bonds of cytoplasmic proteins. When dehydration occurs under the influence of ice formation, the convergence of protein molecules occurs. The bonds between them break and are not restored in their previous form due to too strong convergence and deformation of protein molecules. Concerning great importance has the presence of sulfhydryl and other hydrophilic groups, which contribute to the retention of water and prevent the convergence of protein molecules. The rearrangement of the cytoplasm contributes to an increase in its permeability to water. Due to the faster outflow of water, the risk of intracellular ice formation is reduced.

The temperature of the soil or artificial nutrient medium is of great importance when growing plants. Both high and low temperatures are unfavorable for the life of the root. At low temperatures, the respiration of the roots is weakened, as a result of which the absorption of water and nutrient salts decreases. This leads to wilting and stunting of the plant.

Cucumbers are especially sensitive to a decrease in temperature - a decrease in temperature to 5 ° C destroys cucumber seedlings. The leaves of adult plants at a low temperature of the nutrient solution in sunny weather wilt and get burned. For this crop, the temperature of the nutrient solution should not be lowered below 12°C. Usually in winter time when growing plants in greenhouses nutrient solution stored in tanks has a low temperature and should be heated to at least ambient temperature. The most favorable temperature of the solution used for growing cucumbers should be considered 25-30°C, for tomatoes, onions and other plants - 22-25°C.

If in winter it is necessary to heat the substrate on which the cultivation takes place, then in summer, on the contrary, the plants may suffer due to its high temperature. Already at 38-40°C water absorption and nutrients stops, the plants wilt and may die. It is impossible to allow the heating of solutions and the substrate to such a temperature. The roots of young seedlings are especially affected by high temperatures. For many cultures, a temperature of 28-30 ° is already fatal.

If there is a danger of overheating, it is useful to wet the surface of the soil with water, the evaporation of which lowers the temperature. AT summer time in the practice of greenhouse farming, glass spraying with lime mortar is widely used, which scatters the direct rays of the sun and saves plants from overheating.

Sources

• Growing plants without soil / V.A. Chesnokov, E.N. Bazyrina, T.M. Bushueva and N.L. Ilyinskaya - Leningrad: Leningrad University Press, 1960. - 170 p.

The life and development of indoor plants depends on many factors, and the main one is temperature. The influence of temperature on plants can be both positive and extremely negative. Of course, it all depends on the type of plant and its preferences in the wild, but some species lose their original habits and fully adapt to apartment conditions.

Each type of plant needs a different amount of heat, some of them can endure deviations from acceptable temperature conditions, while others suffer and are inhibited in development.

An important factor is not only the amount of heat received by the plant, but also the duration of the heat exposure. At different stages of a plant's life, the amount of heat required often varies, so at the stage of active growth, most plants need a warm atmosphere, but when the plant goes into a dormant period, it is recommended to reduce the amount of heat received.

The comfortable temperature for each plant is determined based on the maximum and minimum temperatures at which the plant develops normally or feels comfortable at different stages of life. A temperature drop below acceptable values, as a rule, leads to the attenuation of all processes, inhibition of development and weakening of the photosynthesis process. An increase, on the contrary, activates and accelerates these processes.

In the cold season, the effect of temperature on plants is slightly different. Plants will be comfortable at lower temperatures, this is due to the fact that most plants go into a dormant phase during this period. At this time, the growth process slows down or stops altogether, the plant seems to be sleeping, waiting for more favorable conditions. Therefore, there is no reason to maintain a high temperature during this period, the need for heat by plants is much less than in summer.

• able to withstand sudden changes in temperature
• thermophilic
• cool content lovers

The first group includes aspidistra, aucuba, clivia, monstera, ficuses, tradescantia and even some types of palm trees. Fans of warm conditions in winter include orchids, coleus, and others. These plants suffer from a lack of heat and can die, so their maintenance must be approached responsibly. The third group includes jasmine, cyclamen, boxwood and others. These plants will feel good in cool rooms at average temperatures of 8-12 degrees.

Usually representatives of the third group cause difficulties, because in the cold season it is problematic to create cool conditions. Yes, yes, no matter how ridiculous it may sound, but it is exactly so. People themselves are by nature thermophilic, and not many of them want to live in cool conditions for the sake of indoor plants, and besides, heating sometimes fries, so at least open the windows for plowing =)

To create cool conditions, you can put such plants on window sills, but in this case it is necessary to protect them from the heat of heating systems, for example, by fencing off with a protective screen or by slightly reducing the heating

If the effect of temperature on plants can be different, then sharp temperature fluctuations will definitely have a negative effect. This often happens, especially in winter. Rapid changes in temperature can adversely affect the root system of the plant, overcool the roots and leaves, as a result of which the plant can become sick. Most of all, plants standing on window sills are subject to such drops, where they are in the position “between the hammer and the anvil”. On the one hand, heat from the battery presses, and on the other hand, cold when airing and frozen windows.

Of course, tropical plants are most sensitive to drops, but cacti endure even strong jumps. By nature, their cacti are in conditions where day and night temperatures can differ by tens of degrees.

When airing rooms, plants must be protected, especially those that are on the windowsill. For this purpose, you can use a sheet of cardboard, if there is nothing to protect the plants - it is better to remove them away from the window for the time of airing.

The article gives general information Naturally, the effect of temperature on plants of specific species can vary greatly. It is better to get acquainted with the recommended temperatures for individual plant species in the catalog.

Plant growth is highly dependent on temperature and can occur from zero to 35°C.

The growth rate at temperatures above 35-40° decreases, and with a further increase it turns.

Different plants have different attitudes to temperature. Some plants are thermophilic and require higher temperatures for their growth. Other plants are more tolerant of low temperatures and sensitive to excessive temperatures.

Regulating temperature regime in combination with other living conditions, growth can be controlled, i.e., suspended or brought to an optimal level. At the same time, it must be borne in mind that it is impossible to act with heat to accelerate or slow down growth without providing the plant with light and moisture.

To quickly get stocky plants, you need more light, heat and moisture (up to optimal sizes).

The effect of temperature on the plant is very often used in greenhouses. For accelerated growth, plants are provided with an elevated temperature from the early phases of development to flowering. This technique accelerates the growth and development of the plant, but it is not always taken into account that plants grown at a higher temperature turn out to be weaker in vitality than those developed at a lower temperature. Plants grown in greenhouses at a higher temperature quickly lose their decorative effect in living quarters.

When cultivating plants in greenhouses, you need to pay attention to this and not release products for sale that quickly die in the rooms.

An example of an erroneous temperature effect on plants can be the cultivation of summer seedlings at elevated temperatures. Seedling is obtained by appearance good, but poorly adapted to the hardships of open ground (short-lived).

If the plant finishes its growth earlier than the scheduled time, it is placed in a room with a low temperature to retard growth. If the plant is not squat, but rather stretched out, it is placed in a cooler room for the night. For greater decorativeness of plants, it is always necessary to lower the temperature in the rooms at night. A gradual and temporary decrease in temperature, repeated several times, increases the resistance of heat-loving plants to low temperatures.

An increase in the cold resistance of plants is achieved by sowing seeds directly into open ground. In this case, seedlings withstand frosts of 2-3 °. Seedlings of many plants grown in greenhouses and greenhouses die in the soil at -1, -2 °.

Increasing the resistance of plants to low temperatures can be achieved by breeding cold-resistant varieties, "cooling" the seeds, etc.

The temperature regime also affects the exit of seeds from dormancy (stratification), as well as their subsequent germination. This mode is also important for passing the dormant period. Plants that come from northern latitudes need organic rest. Without going dormant at low temperatures, they will not grow and develop well in the future. To speed up the passage of organic dormancy, you need to provide the plant with a low temperature.

If it is necessary to postpone the onset of dormancy or extend its period, the plant is provided with conditions unfavorable for the passage of organic dormancy, i.e., they do not give an appropriate low temperature.

If organic dormancy has passed, in order to retard growth or prolong forced dormancy, the plants are again placed in conditions of low temperatures.

An increase in temperature during forced rest reduces the latter.

To delay the germination of some tubers, bulbs and seeds, snow is used or trenches with frozen soil are used to keep them.

Keeping seeds in early spring at a temperature of 5-20 °, especially in sunlight, ensures their ripening within 7-10 days; at temperatures around 0 this process is very slow. The elevated temperature in August promotes the ripening of the bulbs.

For plant growth retardation open field in spring, trampling down snow and covering it with manure around the plant affects.

The air temperature also affects the respiration of plants, which becomes more intense at elevated temperatures.

In winter, when savings organic matter in low light almost does not occur, it is necessary, by providing the plant with a slightly lower temperature, to reduce the intensity of respiration. This also applies to bulbs, tubers and rhizomes stored in winter.

When caring for indoor plants, it is important to observe the temperature regime that is suitable for them. After all, in wild nature each of them grows in a certain climatic zone and is adapted to these conditions of existence.

At home, it is almost impossible to create a climate for them in the tropics, subtropics or semi-deserts, but you should try to observe a similar temperature regime, otherwise the plant may lose its decorative effect, and even die.

In the article we will consider the effect of temperature on plant growth and development.

The effect of temperature on plants

If a plant is provided with the temperature to which it is adapted, it grows well, develops and blooms profusely. But often flower growers have difficulties in ensuring the desired temperature regime.

Despite the fact that many indoor flowers come from the tropics, they do not tolerate high temperatures.. In their native climate, the summer heat is accompanied by increased humidity, in contrast to the climate middle lane. Therefore, often with an increase in temperature, drying is observed first of the tip, and then of the entire sheet.

As well as an increase in temperature, for many plants its lowering is harmful.

Low temperatures in the room, accompanied by an increase in humidity, are typical for the autumn and spring periods before turning on and after turning off the heating. At this time, cases of decay of the root system of plants become more frequent, and if the temperature drops significantly, their leaves can curl up and fall off. Plants also react to a sharp drop in temperature.

High temperature for plants

Not all houseplants tolerate summer heat well. Many of them suffer from high temperatures and low humidity in areas temperate climate. To protect indoor flowers from unusual temperatures, apply abundant watering, spraying and shading.

Tropical summers are characterized by high humidity. At the same time, plants easily tolerate temperatures up to 30ºС. An increase in humidity in the room is facilitated by good moistening of the earthy coma and spraying the leaves of the plant.

For residents of the tropics, in addition to frequent watering, it is suitable to install the pot in a tray with moistened sand. Spraying can be done daily with water at room temperature.

Often the plant in the summer suffers not so much from the high temperature, but from the action of direct sunlight. In order to avoid burns on the leaves, and at the same time to reduce the temperature of the air in which the plant lives, you need to put it in the shade or cover it from the sun with white paper.

The effect of low temperatures on plants

Winter maintenance of indoor plants is always different from summer.

In winter, most plants need it, because in their homeland the temperature regime is changing. Usually indoor flowers should not grow in winter, and for this they are kept at low temperatures and weak watering.

There are species that are insensitive to temperature changes and do not have a pronounced dormant period. The rest should hibernate at temperatures to which they are adapted.

Plants tolerant of temperature extremes

Some unpretentious species almost do not react at all to a decrease or increase in temperature. They are very resistant to temperature influences and do not require the maintenance of any particular temperature in the winter.

These are such decorative leafy plants:,. They can be kept in winter at room temperature, but they can withstand a decrease in it to plus 5-10ºС.

Many coniferous species growing in withstands even short frosts. Pelargonium is also very hardy, which sheds leaves only when the temperature drops below 0ºС.

Consider the groups of plants in relation to temperature.

This article is often read:

heat loving indoor plants

There are many species that do not tolerate low temperatures. If the air temperature drops to 10-13ºС, their leaves curl up and fall off.

Such heat-loving tender plants include:,, fittonia. The optimum temperature for their wintering is 15-20ºС.

Plants that need cool

Cool wintering is needed mainly for flowering plants, which, after a dormant period, begin to grow intensively and bloom. It , .

Among those wintering in coolness there are also ornamental leafy plants.. These are some types of ficuses, ferns, Kalanchoe. All these plants are recommended to be kept in winter at a temperature of 8-15ºС.

Plants requiring cold storage

Among indoor flowers, there are those grown at low room temperature. These are mainly succulents, which should not grow in winter. The growth of succulents with a shortened light day leads to elongation. They weaken, lose decorative look, do not bloom.

Almost all types of cacti require wintering at a temperature of 5-8ºС with very rare watering once a month or less. At the same temperature, some species, aeoniums, hibernate.

Agave can also be kept at lower temperatures - up to 0ºС.

Many bulbous crops and gloxinia tubers also contain in winter at temperatures around 8ºС, which stimulates their growth and flowering in spring.

We examined the classification of plants in relation to temperature.

Protection of flowers during airing

Airing is necessary for indoor plants, as they need fresh air. They especially experience this disadvantage in winter, when the windows are closed due to the winter cold. However, winter ventilation must be carried out very carefully so as not to lower the temperature in the room sharply and not harm the plants.

You can do a gradual ventilation of the room through the intermediate room, the air of which has already been updated.

In this case, fresh air will gradually move into the room with plants and will not lead to a strong decrease in temperature.

The easiest way to air the room is to take the flowers to another room..

Especially you need to take care of those plants that are closer to the window, because there the temperature can reach the limit values ​​​​for them. It is recommended to bring them back only after the temperature regime returns to normal.

In addition to lowering the temperature during ventilation, there is also a risk of drafts. Many species react negatively to drafts by dropping leaves, and this can happen even in summer. Therefore, it is necessary to ensure that indoor flowers do not end up in a draft, remove them when opening windows.

Plant adaptation to high temperatures

The ability of plants to adapt and tolerate exposure to high temperatures is called heat tolerance. Heat-loving flowers can withstand prolonged overheating, while moderately heat-loving - short-term.

To protect against high temperatures, plants use different kinds adaptation.

Morphological and anatomical devices are a special structure that helps prevent overheating. These traits include:

• Shiny surface of leaves and stems, reflecting sunlight;
• Dense pubescence of the plant, which enhances the ability of the leaves to reflect and gives them a light color;
• The meridional or vertical position of the leaves, which reduces the surface that absorbs the sun's rays;
• General reduction of leaf surface.

All these features also help the plant lose less water.

Physiological adaptations include:

Plant resistance to low temperatures

There are no special properties of plant adaptation to low temperatures. However, there are devices that protect against a complex of adverse conditions - wind, cold, the possibility of drying. Among them are:

• Pubescence of the renal scales;
• Thickening of the cork layer;
• leaf pubescence;
• Thickened cuticle;
• Resining the kidneys for the winter in conifers;
• Special forms of growth and small size, for example, small leaves, dwarfing, close internodes, horizontal form of growth;
• Development of thick and fleshy contractile roots. At the end of autumn, they dry up and decrease in length, drawing bulbs, roots, wintering buds into the ground.

Physiological adaptations help lower the freezing point of cell sap and protect water from freezing. These include:

• Increased concentration of cell sap;
• Anabiosis is the ability to suspend life processes in a plant under extreme conditions and reduce productivity.

Which plants are affected by temperature fluctuations?

Both throughout the year and throughout the day there are natural fluctuations in temperature. How various plants tolerate such fluctuations?

Most indoor flowers do not tolerate strong temperature fluctuations.. So when it gets colder by 6-10 degrees, the leaves of dieffenbachia begin to turn yellow and fade, and growth stops. The same "symptoms" can be observed in other plants. Therefore, when airing a room in winter, it is better to remove the flowers from the windowsill.

It is important to know that a gradual change in temperature, at a rate of no more than 0.5 degrees per hour, can tolerate most plants.

However, there are plants that normally tolerate even large temperature fluctuations. These include aloe, sansiviera, clivia, aspidistra, and others.

The most thermophilic, and therefore poorly tolerated by strong temperature changes, are flowering and decorative-deciduous representatives of the aroid, begonia, mulberry and bromeliad families.

The most heat-loving variegated guests from the tropics: caladium, codiaum.

Natural temperature fluctuations at home

In nature, there is a rhythmic change in temperature: at night it decreases, and during the day it rises. The same changes occur throughout the year, when the seasons smoothly change one after another.

Plants, in their natural environment, adapt to such changes.. Indoor flowers, which naturally grow in temperate latitudes, tolerate changes in the amount of heat well, while for guests from the tropics such temperature fluctuations are more painful.

Therefore, in the cold season, tropical plants have a pronounced dormant period. For them, it is very important, because it has a positive effect on further growth and development.

It is important to know that indoor plants will be beneficially affected when the temperature in daytime will be several degrees higher than at night.