THE FROST FACTOR. 147 



TIMES FOB PLANTING CERTAIN VEGETABLES IN VALLEY AND FOOTHILL 

 REGIONS OF CENTRAL AND NORTHERN CALIFORNIA. 



till I III III! 



Beans * * * * * 



Beets * * * * * * * 



Cabbage * * * * *.. * * * * *.. 



Carrots * * * * * * * 



Cauliflower ... * .. .. * * * * * * 



Celery ,.; v -* > - : ,* * * * 



Corn * .. >v .-,.; '.,- .-*-v-'-i.*: -V.. : /..<; V. * * 



Cucumbers .... * . . ......,,.' . . * * * 



Eggplant "'' " '' "'" '. ' / . 



Lettuce * * * * * * * * * * * * 



Melons * <&. ; '.. ^.." .. .; \. 'i.-/.. * * * 



Onions * * * * * * * * * 



Peas * * * * * * * * * .. 



Potatoes * . >' *******.. 



Potatoes, sweet. . . ' ' '> ; - '.VI ''..'.'.''* * * * 



Radishes * * * * * * * * * * * * 



Salsify * .. .. .; .. .w .. * * * .. .. 



Spinach * * * .. .. .. 



Squash * * * * 



Tomatoes * * * 



Turnips ..* *.. * *.. * * * * * * 



4 On irrigated or naturally moist low land. 



THE FROST FACTOR. 



The intrusion of the frost period is a local limitation of 

 the planting season. Each vegetable grower should keep 

 records of frost occurrence for his own guidance in future 

 operations and for the public benefit, for the government 

 weather service is very anxious to get local observations 

 on this point. 



During the last decade the San Francisco office of the 

 U. S. Weather Bureau has given particular attention to 

 frost phenomena, including conditions of occurrence and 

 prevention, and the publications by the local officer in 

 charge, Prof. Alexander G. McAdie, comprise the best 

 knowledge on the subject. 



The discussion in the chapter on California Climate as 

 Related to Vegetable Growing shows that weather condi- 



