BENEFITS OF DRAINAGE 73 



discussion, contemplated artificial drainage may have the power to 

 make or ruin a crop if its action is not intelligently employed, or in- 

 telligently rejected, as the case may require. 



Benefits of Drainage. It may be admitted at the outset that 

 in regions of heavy rainfall or in locations subject to much percola- 

 tion from higher lands, underdrainage may be necessary to satis- 

 factory use of the land in winter gardening unless the soil is deep 

 and free enough to readily dispose of the surplus water. As a 

 matter of fact, it is necessary in some cases, and gratifying results 

 follow in lowering the .ground water, admitting air, warming the 

 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 most 

 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 a later 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 



