VEGETABLE GARDENING. 29 



not be applied to them, but for some of the very stiff sub- 

 soils of this section it is a great improvement, since it deepens 

 the tillable land so that the roots of the plants can push more 

 readily into it. This loosening- of the stiff subsoil also puts 

 it into just the right condition for receiving and holding 

 water. It is thus sometimes a great help in carrying plants over 

 droughty periods. Subsoiling gives best results when per- 

 formed in the autumn. If done in the spring and the oper- 

 ation is followed by dry weather, the land is apt to be left too 

 loose to hold moisture well that year and consequently will suffer 



Figure 3.— Root of onion plant with earth washed off. The roots went to 

 the depth of eighteen inches in the earth. 



from drought. It is seldom, even on stiff land, that subsoil- 

 ing is needed more than once in four or five years, for after 

 being- once loosened the roots of plants penetrate it and keep 

 it open. The roots of our garden crops push deeper into the 

 land than is generally understood : even the onion, which is 

 perhaps as shallow rooted as any garden crop grown, often 

 pushes its roots to a depth of eighteen inches in good soil, 



