22 CALIFORNIA GARDEN FLOWERS. 



Plants can be protected from freezing by freely wetting the ground 

 around them, by running water alongside in a ditch or by placing a 

 bucket of water close to the plant. This is effective against four or 

 five degrees of frost for ,an hour or two. The protection is secured by 

 the latent heat set free by the cooling of the water. 



Plants can be saved from injury by freezing by the building of fires 

 of damp litter on the windward side so that a cloud of smoke envelops 

 them during the low temperature. This is also effective against four or 

 five degrees of frost for several hours. The action is two-fold, first 

 by checking radiation second by preventing touch of sunshine which 

 may cause rupture of tissues by too rapid thawing. A slow rise in 

 temperature may permit slow thawing without rupture, if the freezing 

 has not itself been hard enough to break the tissues. The same result 

 is obtainable by drenching with cold water, plants which have been 

 lightly frosted. Obviously this must be done before sunrise. 



Plants may be protected by direct action of heat from brush fires, 

 fires of inflammables in small pots or stoves, etc., which have shown 

 ability to raise the heat of the lower layer of the surrounding atmos- 

 phere six or eight degrees, under favorable conditions of air movement 

 which does not replace the warmer air too rapidly. This method of 

 "heating all out of doors" was first proposed and reduced to successful 

 operation in California by the growers of citrus fruits. It is of course 

 available for the protection of all tender plants. Wiring areas for 

 protection by heat from electric lamps is also practicable but ap- 

 parently more costly in outfit and operation, but invention in this line 

 is still in progress. Manifestly one can wire a garden for illumination 

 and night enjoyment and at the same time provide for frost prevention. 



