258 GARDENING FOR THE SOUTH. 



Iii Florida protection against frost is secured by the 

 use of laths fastened with wire (the space between each 

 being the width of the lath). This screen spread over the 

 plants greatly retards the radiation of heat from the 

 plant, and reduces the chances for frost. 



Mr. E. L. Koethen, a member of the Frost Protection 

 Committee of the Riverside Horticultural Club, of Cali- 

 fornia, gives the following excellent data concerning his 

 experiments on protection against frost. The conclusions 

 are of great interest to all fruit-growers: 



1. In sections where there is a prevailing draft from a certain direc- 

 tion concentrate the fires somewhat on. the sides of the orchard from 

 which this draft comes. 



2. Some fires are needed all through the orchard. 



3. If the thermometer should reach 26° by midnight, start firing at 

 once. If smudging is to be depended upon, you should commence much 

 earlier. To be safe, commence lighting baskets, if the thermometer 

 should reach 26° as late as 4:30 A. M. 



4. Ripe fruit will stand more frost than green fruit. The above 

 figures are for ripe fruit. 



5. The thermometer may go many degrees below the dew-point in 

 our climate on nights when the sun sets behind heavy clouds. 



6. A mild day may be followed by a night of danger to citrus fruits. 



7. The upper strata of air are much warmer than the lower. Eight 

 degrees was found to be the variation between a height of 5 and 50 

 feet, upon different tests. 



8. Thermometers should be tested each year, and the variation noted 

 and accounted for at each reading. 



9. A good way to secure uniform observations and the extreme tem- 

 perature to which fruit is exposed is to fasten the thermometer to a 

 slender stick five feet long and place in the space between four trees, 

 away from buildings or other shelter. 



10. Every grove has some spot that is colder than any other. Find 

 it, and be governed in your firing by the temperature there, keeping 

 your eye en other locations, for the coldest place may shift around. 



11. A thermometer that registers too high may be very comforting, 

 but is not a safe guide unless allowance is made for correction. 



12. A thermometer that registers too low may cost unnecessary 

 labor, expense, and anxiety. 



