6o 



crops grown successfully from season to season. 

 Few first-class gardeners fail to treat the soils of 

 their seed beds at least once each year. No suc- 

 cessful greenhouse manager attempts to grow crops 

 continuously without thorough disinfection of the 

 soil to a considerable depth at least once each 

 season. 



Three common methods of soil disinfection are in 

 use. Perhaps the most widely and most success- 

 fully used plan is by steam. Frames of perforated 

 iron pipes of convenient size for handling are at- 

 tached to the steam pipes by means of steam hose, 

 which allow of considerable freedom of movement. 

 They are usually about one-half as wide as the beds to 

 be treated, but this is not an important detail. The 

 frame is placed on one side of the bed and the soil 

 on the other side is shoveled over it to the depth of 

 four or five inches and covered with burlap of some 

 sort. Live steam is then turned into the pipes and 

 left for several hours. The process is continued 

 <iown the bed, then the frame is placed in the bot- 

 tom of the side from which the soil had been re- 

 moved and again covered and treated. This treat- 

 ment, if carefully done, destroys all the germs of 

 diseases present in the soil and at the same time 

 seems to have a considerable influence in increasing 

 the productiveness of the soil. 



Formalin has been successfully used and has the 

 advantage of requiring considerably less work than 

 the steam method. The beds are thoroughly pre- 

 pared for planting with the exception of the addi- 

 tion of the commercial fertilizers and then thor- 

 oughly drenched with a formalin solution of one gal- 

 Jon of commercial formalin to 150 to 200 gallons of 

 water. About one gallon of this diluted solution 



