74 
FLORIDA STATE HORTICULTURAL SOCIETY 
burned these heaters but twice, but those 
two times were sufficient to demonstrate 
to us that, even though the cost is high 
and the depreciation both of pots and oil 
is large, the insurance afforded is remark¬ 
ably cheap. One night the weather bu¬ 
reau predicted a frost; the wind was in 
the northwest and the conditions seemed 
to warrant the report. We fired up when 
the thermometer went to 28, and by the 
time the men in one 5-acre grove had the 
pots all lit and got back to look at their 
thermometer, it had gone to 38. Half of 
the pots were extinguished entirely. 
It went to 36; the other half were shut 
down very low. The thermometer 
went to 33 where it was held until 
morning. The thermometer outside of 
the grove showed a minimum of 26 de¬ 
grees. The makers recommended 50 
of these pots to the acre. We use 75, 
and have them double thick for two 
rows on the north and west sides of 
the grove. We have since then bought 
one thousand heaters of another make 
and expect this summer to put in more, 
as we firmly believe they will do the 
work. 
As to the equipment necessary to 
protect a grove against a freeze I can 
recommend the following: I do not 
feel that in a paper of this kind I am 
justified in recommending any make of 
heater, but whatever heater you decide 
on use more per acre than the makers 
recommend. Get a heater that will 
not require refilling during the night. 
If it is a large heater that makes a 
good, big fire, 50 or 75 to the acre may 
be enough. 
As to oil, have enough oil on hand to 
burn until you can get another supply. 
If it will take five days to get another 
supply of oil have enough on hand to 
burn at least five nights. You will need 
tanks to hold your surplus oil and tank 
wagons to distribute the oil. These 
may be had from various makers here 
in the State. We have a concrete res¬ 
ervoir for our main supply, but I un¬ 
derstand some people who have used 
concrete have had trouble with the oil 
leaking out, though we have not our¬ 
selves. 
You will need two or three good ther¬ 
mometers ; this is an item on which you 
are going to hang your crop of fruit, so 
don’t economize on it. Get a thermome¬ 
ter that has been government-tested, 01 
that has been compared with an absolute¬ 
ly accurate thermometer. In order to be 
safe it should not vary more than one de¬ 
gree. Get a wet and dry bulb thermome¬ 
ter, and write the weather bureau for di¬ 
rections how to use it. This latter may 
save you many a sleepless night. You 
will want two torches and two gasoline 
cans for each ten acres of grove, as we 
find that one man can handle about five 
acres. 
The cost of this equipment will depend 
so much on locality and the make of 
smudge pot, that I shall merely give you 
the figures that were printed in the Flor¬ 
ida Grower of March 21, 1914, in an 
article by Mr. James D. Culbertson of the 
Limoncira Company of Santa Paula, 
Calif. I have had some correspondence 
with Mr. Culbertson and feel that his ar¬ 
ticle is the best on the subject of frost pro¬ 
tection I have ever seen, and can heartily 
recommend it to anyone for careful study. 
