CHAPTER X 



SOIL FOR GREENHOUSES, ITS FERTILITY 

 AND PREPARATION 



THE success or failure of the flower-grower depends in 

 a large measure upon the character of the soil. In the 

 larger number of cases where plants are unhealthy, and 

 results unsatisfactory, soil conditions are responsible. 



As has been stated in Chapter VIII, healthy root growth 

 and development cannot take place unless soil moisture, 

 heat and aeration conditions are correct. In addition to 

 these requisites, there should be proper amounts of plant 

 food in forms that plants may readily use. 



142. Classification of soils. Soils are generally clas- 

 sified according to the size of the particles, as follows : 



Fine gravel .... . 2 to 1 mm. 



Coarse sand 1 to 0.5 mm. 



Medium sand 0.5 to 0.25 mm. 



Fine sand 0.25 to 0.1 mm. 



Very fine sand ... . * 0.1 to 0.05 mm. 



Silt ..;._.. 0.05 to 0.005 mm. 



Clay 0.005 to mm. 



143. Value of the different classes in greenhouse 

 work. No one of these soils, if used alone, is ideal for 

 the growth of any species of plants under glass. 



When large numbers of plants are to be propagated by 

 cuttings, however, it is necessary to have available an 

 abundance of sharp sand of medium texture. This is es- 

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