In some kinds of hardpan, like cemented gravel, it may be necessary 

 to vary a little the instructions given above. These instructions will, 

 however, answer for a guide until practice shows that some slight 

 changes in the way of blasting these irregular hardpans will prove of 

 advantage. If properly done, it may not be necessary to blast subsoil 

 or hardpan more often than once in ten years. In orchards in California 

 hardpan, heavier charges are sometimes used in the boreholes so that the 

 blast will leave a considerable opening, which can be filled with special 

 fertilizers. Subsoil blasting should be done onlv when the ground is 

 dry because ivct subsoil is not easily cracked and shattered, and tends to 

 come up on top, leaving a large hole where each blast was fired. 



Tree Planting 



The method to be employed in doing this work is to punch a hole 

 in the ground at the point selected for planting the tree, to a depth of two 

 to five feet according to nature of soil, and location of hardpan, if any. 



In very tight soils, as in California hardpan a whole cartridge of 

 Red Cross Extra 20% or even 40% may be necessary. These heavy 

 charges should be tamped. 



The usual charge is one-half cartridge of Red Cross Extra Dyna- 

 mite 20% per hole, primed with cap and fuse. If the soil in which the 

 tree is to be planted is of a hardpan, shale or very compact clay, holes 

 should be tamped, as also in the case when pecan trees are planted, other- 

 wise no tamping is necessary. 



The common practice is to plant the trees shortly after the holes are 

 blasted. Some orchardists, however, believe best results will be obtained 

 when holes for Spring planting are blasted in the Fall. 



This affords about six months time for the air, moisture and sun- 

 light to work on the subsoil and mellow it. 



If trees are planted immediately after the blast, care must be taken 

 to poke down the upheaved soil at the bottom of the hole or settle it well 

 with water. If this is not done, the dirt may shrink away from the roots 

 of the tree, leaving is suspended in air or water and thus killing it. This 

 is undoubtedly the cause of the death of the few dynamite-set trees 

 reported as failures. A little care in settling the dirt will prevent this 

 trouble. 



Table of Charges and Amount of Red Cross Extra Dynamite 

 20% Required per Acre for Planting Trees 



*It is necessary to have as many feet of fuse per hole as the hole is deep. 



154 



