Plant Frost Damage

the destruction of plants or parts of plants by the formation in their tissues of ice caused by frost.

The water in plant cells and in the interstices between cells begins to freeze at a temperature of -1° C. The ice destroys the invisible (submicroscopic) structure of the cells and causes their death. At first the water in the cellular interstices freezes; then with a further drop in temperature the water in the protoplasm freezes. Depending on the species, type, and physiological condition of a plant, frost damage takes place with varying amounts of ice in the cells. Potatoes, tomatoes, beans, cucumbers, and cotton plants freeze at -2° C. Frozen but not yet dead plants can die as a result of extremely quick thawing, which causes changes in the structure of the protoplasts; with slow thawing of these plants the still-living cells gradually absorb water and retain their vital capacity. Apples, pears, and onion bulbs are especially damaged by quick thawing.

Methods of combating frost damage are based on increasing the frost resistance of plants. Several specific techniques are employed to protect fruit orchards against freezing, including smoking and various means of covering them.