266 The Principles of Fruit-growing 



Some of the methods in orchard-heating are here 

 quoted and adapted from O'Gara, who has had much 

 experience in Oregon and has written effectively on the 

 subject. 



The number of heaps or piles of home material which should be 

 distributed in the orchard will vary somewhat, depending upon the 

 kind of material used, about forty to fifty piles to the acre being 

 usually sufficient. In most cases a heap or pile was placed between 

 every four trees — that is to say, a pile every other tree row in each 

 direction in the orchard, as Fig. 96, which illustrates the preparation 

 in an apple orchard. Usually it will be found that only half of these 

 heaps will have to be lighted at one time, which of course allows a 

 large amount of reserve material that may be used in case it is 

 impossible to keep the temperature up with only half the fires 

 lighted. It is also well to place heaps of fuel on the outer edges or 

 borders of the orchard, since it is often found that the outside trees 

 may suffer where a sUght breeze tends to blow the heat away. 

 These piles should be distributed outside the last row of the orchard, 

 and in case the temperature can not be kept up they should be 

 lighted. 



In case the temperature can not be kept up to 28° F., a certain 

 quantity of straw or stable manure, which will produce a dense 

 smudge, should be placed upon these heaps before the sun rises. 

 These smudges should be started on the side or sides from which 

 the wind is blowing, and the material should be wet, so as to make 

 it bum without any flame. 



Experience has shown that the fires should not be large, since 

 large fires tend to produce convective currents that are apt to bring 

 in cold air; hence, the quantity of material for each heap need not 

 be very great. Large fires also might scorch the blossoms. From 

 four to five pieces of cordwood, or its equivalent in any other kind 

 of wood or old rails, are sufficient for a single fire; very often when 

 the low temperature is of short duration all of this material will not 

 be consumed in a single firing. In case stable manure or rubbish was 

 used, a larger number of heaps were placed, and the quantity of 

 material to each heap averaged about a bushel or a bushel and a 

 half. 



