76 CALIFORNIA VEGETABLES. 



its escape. It is especially important in an arid country 

 that the lower strata of the soil should be a storage reser- 

 voir for the use of the plant in the dry season. This 

 fact underlies the recommendations for cultivation which 

 will be given in a later chapter, but it also has intimate 

 relations with the subject of drainage. Evidently, re- 

 course to drainage should not endanger the generously 

 adequate moisture supply which the plant needs, and 

 for this reason the almost universal exhortation in gar-^ 

 dening treatises for humid climates: "first of all, deeply 

 drain your soil," either subject the trusting Calif ornian to 

 a useless expense, or, worse than that, makes his land less 

 suited to his purpose than it was before the expenditure 

 was made. 



For it should be noted : first, that our light deep loams 

 which are chiefly used for garden purposes, can naturally 

 dispose of all the surplus water which the clouds afford 

 them; second, our heavier soils sometimes make a great 

 surface show of saturation when the lower layers have 

 really far less than their holding capacity, because per- 

 colation is slow, not only by nature of the soil but by the 

 lack of thorough tillage which would help to hold a large 

 precipitation until the soil could absorb it; third, our 

 soils dispose of moisture very rapidly during the dry in- 

 tervals of the rainy season, and this can be increased by 

 winter cultivation which should not aim to fine the sur- 

 face but to open it to the air; fourth, by their active 

 winter growth, the plants themselves pump from the sur- 

 face layer volumes of water, the escape of which opens 

 the way for capillarity to relieve lower layers of their 

 surplus, and thus the active roots help to prepare the 

 way for their own farther extension. 



Really, then, what California soils need for winter gar- 

 den purposes is natural surface drainage, viz., downward 

 into thirsty lower layers: upward into the air by evap- 

 oration from earth-surfaces or plant-surfaces. Where 

 this is not adequate to the relief of surface saturation 



