Frosts in New York 525 



methods of frost protection 



The object sought in all methods of frost protection is to hold the tem- 

 perature of the air in contact with the plant above the point of danger. 

 In the attempt to accomplish this certain principles are involved: 



1. Prevention or retardation of the escape of heat from the earth by 

 the use of an artificial covering. The use of smudges as a means of pro- 

 tection against frost is based on this principle. 



2. Addition to the air of moisture in the form of vapor, with the view 

 of obtaining the effect of liberation of latent heat as the moisture condenses. 

 The use of damp fuel for smudges and the spraying of fires with water 

 have this purpose in view. 



3. Heating the air by numerous small fires. 



Artificial covering 



It is a very old practice to protect plants from frost by covering them 

 with newspapers, carpets, straw, and the like. This is a most cleanly 

 and efficient method, but unfortunately, because of the labor and expense 

 involved, it is applicable in practice only to small areas, such as flower 

 beds and gardens. However, by a small investment in tarred building 

 paper the practice may be extended profitably to considerable areas. 

 When the paper is cut into convenient lengths and two or three strips are 

 fastened or pasted together so as to make a strip eight or ten feet wide, 

 which can be rolled and unrolled easily, this method may be used for the 

 protection of a fairly large area. It affords a very convenient and efficient 

 protection for strawberries, garden truck, or small fruits. Paper of this 

 kind can be purchased for one to two cents per square foot, and with care 

 should last several years. 



Smudging 



Smudging, particularly when damp fuel is used, combines the first and 

 second principles mentioned above — the prevention of the escape of heat 

 from the ground and the addition of moisture to the air. In practice 

 smudging has not proved a very efficient method of protection. It is 

 used chiefly at present to shield the blossoms from the sun during the morn- 

 ing hours following a frost, thus preventing too rapid thawing. Spraying 

 the frozen fruit or blossoms with water is practiced, also, with the same 

 purpose in view. It is not so much the freezing that causes injury, as too 

 rapid thawing. It is said that blossoms may be frozen solid for several 

 hours without injury if thawed very slowly. 



