30 CALIFORNIA FRUITS: HOW TO GROW THEM 



The soils prevailing in the valley of Southern California, from 

 Redlands at its head to Los Angeles at it opening out toward the sea, 

 consist chiefly of granitic sand, which at some points on the slopes 

 forms the soils exclusively, but everywhere constitutes a prominent 

 ingredient of the valley and mesa lands. These mesa lands are con- 

 spicuous for their orange-red tint, and the red sandy loam of which 

 they are composed, to depths varying from ten to as much as eighty 

 feet, is evidently the choice soil for orange culture. It is manifest 

 that at some remote epoch it filled the entire valley. Of the middle 

 portion much has been washed away, but islands of it form red-land 

 tracts of greater or less extent all over the region, traversed by and 

 more or less commingled with, the gigantic wash from the valleys and 

 canyons of the Sierra Madre. The latter frequently consists largely 

 of gravel, and were it not for the luxuriant natural vegetation borne 

 by these gravel beds, few would have thought of devoting them to the 

 costly experiment of orange planting, which, nevertheless, has proved 

 eminently successful even on these unpromising-looking masses of 

 debris. In the upper valley (San Bernardino Valley proper) the red 

 loam is conspicuous, and gives its name to the flourishing city and 

 citrus district of Redlands, on the terminal slope; but the heavy flow 

 of water from the upper canyons, notably from that of the Santa Ana 

 River, has scoured it out of the valley itself, and left there, at least 

 on the northern portion, gray and blackish granitic loams of great 

 depth and productiveness, underlaid, and therefore underdrained, by 

 the enormous gravel beds that hold the artesian water of this favored 

 region. 



The reddish mesa soils prevail through the smaller Southern Cali- 

 fornia valleys as well, and are similar in character, as they are derived 

 from similar geological formations. 



Where the surface descends gradually to the seashore, and not in 

 bluffs, there are as in Los Angeles and Orange counties, coast flats 

 several miles in width, where the soil is a dark-colored sandy loam, 

 glistening with scales of mica, and more or less affected with alkali 

 in the lower portions. Similar soils are found in tracts of greater 

 or less extent up the coast as far as Santa Barbara at least. As a 

 rule, these seashore lands are very productive, but fruits for them must 

 be chosen with reference to their low level and exposure to coast 

 influences. 



The light loams of the so-called desert region of Southern California 

 are not inferior in productive capacity to some of the best soils of the 

 great valley, which they greatly resemble, save in the scarcity of 

 humus, or vegetable matter. Only a detailed survey, however, can 

 determine the tracts having an arable soil, as against those overrun 

 by arid sand. The soil of the Colorado River bottom is highly produc- 

 tive, easily worked, being quite light. It is a highly calcareous soil, 

 and now, as the water of the Colorado River has been made available 

 for irrigation, is yielding rich returns for cultivation. 



The valleys of the seaward slope of the Coast Range have mostly 

 gray, light, and silty, rather than sandy soils, quite similar in appear- 

 ance from Ventura to Humboldt county, though differing considerably 



