The plant world is rich and diverse, but not all species are able to survive in harsh climatic conditions. One of the key characteristics of the representatives of the flora is winter hardiness. It is she who determines the viability of plants in a certain area. Based on the frost resistance of the flora, it is necessary to select biological organisms of open soil.
The concepts and features of the winter hardiness and frost resistance of plants
Their ability to withstand low temperatures (within +1 … +10 degrees) for a long period of time depends on the cold resistance of plants. If representatives of the flora continue to grow with negative indicators of the thermometer, they can be safely attributed to frostresistant plants.
Winter hardiness understands the ability of plants to continue their vital activity in adverse conditions for several months (for example, starting from the end of autumn to early spring). Low temperatures are not the only threat to the existence of representatives of the flora. Adverse conditions include sharp temperature differences, winter drainage, bursting, prolonged thaws, freezing, exhalation, sunburns, wind and snow loads, icing, return frosts during the period of spring warming. The reaction of the plant to the aggressiveness of the environment and determines its winter hardiness. This indicator does not apply to constant values, it can periodically decrease or increase. Moreover, the same type of plant has a different level of winter hardiness.
Frost resistance zone in Eurasia
Frost resistance is difficult to confuse with winter hardiness this indicator determines the ability of the plant to withstand negative temperatures. This feature is laid at the genetics level. It is on the degree of frost resistance that the amount of water in the cells, which remains in the liquid state, as well as their resistance to dehydration and the resistance of internal crystallization, depends.
Table of frost resistance zones USDA
|Frost resistance zone||From||Before|
|0||a||−53.9 ° C|
|B||−51.1 ° C||−53.9 ° C|
|one||a||–48.3 ° C||−51.1 ° C|
|B||−45.6 ° C||–48.3 ° C|
|2||a||−42.8 ° C||−45.6 ° C|
|B||–40 ° C||−42.8 ° C|
|3||a||−37.2 ° C||–40 ° C|
|B||−34.4 ° C||−37.2 ° C|
|four||a||−31.7 ° C||−34.4 ° C|
|B||−28.9 ° C||−31.7 ° C|
|5||a||−26.1 ° C||−28.9 ° C|
|B||−23.3 ° C||−26.1 ° C|
|6||a||–20.6 ° C||−23.3 ° C|
|B||−17.8 ° C||–20.6 ° C|
|7||a||−15 ° C||−17.8 ° C|
|B||−12.2 ° C||−15 ° C|
|eight||a||−9.4 ° C||−12.2 ° C|
|B||−6.7 ° C||−9.4 ° C|
|9||a||−3.9 ° C||−6.7 ° C|
|B||−1.1 ° C||−3.9 ° C|
|ten||a||−1.1 ° C||+one.7 ° C|
|B||+one.7 ° C||+four.4 ° C|
|eleven||a||+four.4 ° C||+7.2 ° C|
|B||+7.2 ° C||+10 ° C|
|12||a||+10 ° C||+12.8 ° C|
|B||+12.8 ° C|
Due to which plants become winterhardy?
In addition to the genetic and hereditary factor, microclimate and growing conditions, there are other reasons why plants are resistant to low temperatures:
The winter hardiness of the biological body can change throughout his life. It is believed that young representatives of the flora are less resistant to low temperatures than adults, which often leads to their death.
Representatives of winterhardy plants
Bright representatives of coldresistant plants are barley, flax, vika and oats.
Frostresistant species include perennial organisms of root crop, tuber, onion type, as well as annual spring and bitten winter.
Note that in the cold season of the year, the roots of the plant are most prone to freezing. If negative temperatures prevail in the region, then without a thick layer of snow the probability that they will survive, quite small. In such areas, it is necessary to create an insulating layer, mulching the soil around the plant.
It is at the beginning of winter (in December, January) that plants have maximum winter resistance. But with the onset of spring, even minor frosts can have a destructive effect on the representative of the flora.