62 CALIFORNIA VEGETABLES 



soil, making it hospitable to the plant, rendering fertility available 

 and lengthening the growing season of the plant both by these 

 services and by making the soil sooner amenable to tillage and sus- 

 ceptible of better tilth. All these are general drainage principles 

 applicable here as elsewhere and in some soils and situations the 

 same method of application is best, viz. : thorough under-drainage 

 preferably with tile, but also attainable with trenches partly filled 

 with rock, or with regular runways with placed stones or poles or 

 boards or whatever may be most available to the person at the 

 time. In drainage for garden purposes, however, it is not neces- 

 sary that the water table should be lowered as far as is essential 

 to the satisfactory growth of trees, nor is it desirable generally that 

 it should be. Tile laid two feet from the surface will answer in 

 many cases if the land lies well for the outflow of the drainage. 



Conserving Moisture. The general purpose in California gar- 

 dening must be to save moisture, not to facilitate its escape. It is 

 especially important in an arid country that the lower strata of the 

 soil should be a storage reservoir for the use of the plant in the dry 

 season. This fact underlies the recommendations for cultivation 

 which will be given in abater chapter, but it also has intimate rela- 

 tions with the subject of drainage. Evidently recourse to drainage 

 should not endanger the generously adequate moisture supply which 

 the plant needs, and for this reason the almost universal exhortation 

 in gardening treatises for humid climates : "first of all deeply drain 

 your soil," either subjects the trusting Californian to a useless ex- 

 pense 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 

 percolation 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 cold absorb it; third, our soils dispose of moisture 

 very rapidly during the dry intervals of the rainy season, and this 

 can be increased by winter cultivation which should not aim to fine 

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

 growth, the plants themselves pump from the surface layer volumes 

 of water, the escape of which opens the way for capillarity to re- 

 lieve lower layers of their surplus, and thus the active roots help to 

 prepare the way for their own further extension. 



Really, then, what California soils need for winter garden pur- 

 poses in natural surface drainage, viz., downward into thirsty lower 

 layers; upward into the air by evaporation from earth-surfaces or 

 plant-surfaces. Where this is not adequate to the relief of surface 

 saturation and consequent preparation for seed sowing, very simple 

 artificial surface drainage is usually effective. This can be mainly 



