302 The Principles of Vegetable -Gardening 



ridges or hills wastes the soil moisture in most cases. 

 "Hilling up" is often necessary, however, because the 

 land is not deep enough to allow the tubers to grow 

 well below the surface. The ground should be such as 

 to allow the tubers to be planted at least four inches 

 beneath the level. If the potatoes are dropped in a deep 

 furrow, the earth is plowed over them, and the surface 

 may be harrowed two or three times before the plants 



Fig. 80. A potato plant in deep soil. The old seed-piece is seen 

 near tlie bottom. 



are up, thus conserving moisture and destroying weeds. 

 Land should have been well prepared before the plant- 

 ing in order to render plant -food available and to make 

 it retentive of moisture. Figs. 80 and 81 (both directly 

 from nature) show the habit of the potato plant. 



From five to eight light surface tillings are required 

 during the season in order to save the moisture. Even 

 after the vines have begun to spread and to cover the 

 ground, tillage may be necessary in a dry year. 



The early crop, for market -gardening use, is secured 



