16 CALIFORNIA FRUITS: HOW TO GROW THEM 



are more severe than on the hills adjacent or in the broader valleys 

 to which they are tributary. These small "protected valleys" are 

 apparently warm and cozy for early blooming deciduous and citrus 

 fruits, but they are really very dangerous. They frequently have 

 such narrow and obstructed openings that cold air is dammed up 

 over their lower lands and frosts are more severe and later than in 

 valleys which have ample and free outlets and seem less protected. 



Of course the disposition of cold air to settle in low places and 

 to flow down canyons and creek-beds while the warm air rises and 

 bathes the adjacent hillsides, has much to do with frost in the hollow 

 and the freedom from it on the hills. The constant motion of the air 

 on the slopes is also a preventive of frost, providing the general 

 temperature is not too low. It is not uncommon to find in deeper 

 valleys, protected against the western wind, flakes of snow and a 

 wintry chill, with dormant vegetation, while one thousand feet higher 

 up the foliage is fast developing. 



MOUNTAIN CLIMATE 



Above an elevation of two thousand five hundred to three 

 thousand feet, conditions gradually intrude which 'resemble those 

 of wintry climates. The tender fruits, the apricots, peach, etc., 

 become liable to winter injury and give irregular returns, or as 

 greater elevation is attained, become wholly untrustworthy. Early 

 blooming of these fruits during warm spells which are followed by 

 severe frosts, renders the trees unfruitful. At four thousand to four 

 thousand five hundred feet the hardy apple and pear flourish, ripen- 

 ing late, and winter varieties possessing excellent ' keeping qualities. 

 Here, however, winter killing of trees begins and locations even for 

 hardy fruits have to be choosen with circumspection. 



There are elevated tracts of large extent among the Sierras 

 where the common wild plum, choke-cherry, gooseberry, and Cali- 

 fornia chestnut are produced abundantly. April frosts have killed 

 the fruit of those same plums, transplanted to lower ground, while 

 those left in their natural situation were quite unharmed. It has 

 been observed that these plum trees with other fruits and nuts in 

 their original positions, invariably occupy the broad tops of the 

 great ridges instead of the sides and bottoms of ravines or narrow, 

 pent-up valleys. Follow nature in the choice of orchard sites (with 

 due regard to a supply of moisture in the soil, either natural or 

 artificial) and little hazard attends the culture of the hardier fruits 

 of our latitude among the highlands of the State than is incident 

 to. other seemingly more favored localities. The beauty and quality 

 of these mountain fruits are proverbial. 



A RULE OF GENERAL APPLICATION 



What has been thus suggested of the great variation of tem- 

 perature conditions within narrow limits should lead to the conclusion 

 that not only must the kind of fruit to plant be determined by local 



