68 CALIFORNIA VEGETABLES 



ing. This last method usually limits the practice of autumn garden- 

 ing and emphasizes the desirability of a water supply for irrigation. 

 Sub-soiling may also be done with advantage if the rainfall of the 

 region is generous; if not, there is too great danger that much of 

 the moisture may go out of reach of the shallow-rooting plant. It 

 is usually not as safe to plant as early on newly plowed land as 

 upon replowed summer fallow, for, unless the fall rains are above 

 the average, the plants may be less thrifty than those planted later 

 when full moisture is assured. This is, of course, a matter for local 

 determination as it is conditioned upon local rainfall. It should 

 also be observed that in plowing for early fall planting the land 

 should be harrowed immediately, for there is more danger of losing 

 moisture by evaporation than of getting too much from the early 

 rains, which are usually light. In early plowing to catch winter 

 rains with the idea of planting after the heaviest rains are over, 

 say in February, the early plowing may be left rough until near 

 planting time. 



Even if for any reason it is not thought desirable to plant vege- 

 tables in the open air until February, and this is a practice in locali- 

 ties where fall and early winter temperatures are rather low, still 

 the early plowing is necessary to moisture-saving and cross-plowing 

 should follow in preparation for planting. 



Land designed for spring planting of tender vegetables should 

 also receive early and thorough fall plowing and a subsequent winter 

 plowing or spring plowing before the weed growth becomes too 

 heavy for turning under or so coarse that plowing under will make 

 a non-retentive soil still, more prone to drying out the following 

 summer. 



TILLAGE TO CONSERVE MOISTURE. 



Tillage to receive moisture is designed to open the soil and to 

 assist percolation to prevent surface run-off and to absorb the rain- 

 fall. Tillage to save moisture aims to reduce evaporation to a 

 minimum. In a firm soil moisture rises by capillary attraction and 

 is rapidly removed from the surface by evaporation. A light soil 

 has less capillarity, or ability to draw moisture from below, than 

 a heavy one. A sandy soil has less than a clay, but both lose water 

 by surface evaporation until, in an arid climate, plants will die of 

 thirst unless they be by nature drought resisting. Garden vege- 

 tables are not of that character; in fact quite the reverse. Conse- 

 quently some means must be adopted to prevent the moisture which 

 is rising in the soil from reaching contact with the outer air. This 

 can be done by placing a covering upon the compact portion of 

 the soil so that the air shall not have free access to it. Covering 

 with a sufficient amount of almost any coarse material, such as is 

 commonly known as a mulch, will answer. But the use of coarse 

 manure or rotten straw or sawdust or anything of that sort, is 



