LUTHER BURBANK 



tree that naturally blooms late enough to avoid 

 these frosts. 



This is especially important in view of what 

 has just been said about frosts waylaying trees 

 on a southern exposure, because precisely such ex- 

 posure is of value at the other end of the season, 

 to hasten the ripening of the fruit. This is not 

 only important in the case of fruits designed to 

 meet an early city market, but it applies to many 

 varieties that tend to ripen late in the fall and 

 which thus may suffer from the early frosts of 

 autumn. 



It should be recalled that the warm southern 

 exposure also tends to take the moisture from 

 the soil early in the season, so varieties planted 

 in such a location should be able to resist drought. 



Trees planted on a hillside will probably have 

 natural drainage. Otherwise it may be necessary 

 to drain the soil with tile or with open ditches, or 

 else to select varieties of fruit that are known to 

 thrive in a moist, cool soil. Such varieties must 

 necessarily have an unusually large leaf surface 

 and shallow root system. For this reason they 

 should not be placed where they are subject to 

 heavy winds. 



What may be called air drainage is sometimes 

 quite as important as water drainage. Cold air 

 flows down the hillsides and settles in the valleys. 



[64] 



