AUTUMN COLORS NOT DUE TO FROST \J 



A RULE OF GENERAL APPLICATION 



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

 ature conditions within narrow limits should lead to the conclusion 

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

 observation and experience, but often varieties of these fruits must 

 be chosen with reference to adaptation to local environment. For 

 this reason it is impossible to compile tables of varieties suited for 

 wide areas and yet it is true that some varieties have shown them- 

 selves hardy and satisfactory under all conditions. These facts will 

 be shown by the discussion which will be given to each of the dif- 

 ferent fruits. 



REST AND ACTIVITY OF FRUIT TREES 



Indication has already been made of regions adapted to the 

 growth of early and of late fruits. There is, of course, difference 

 in time of rest and of returning activity in blooming. On the 

 mountains under wintry conditions the trees leaf out and bloom 

 late, following more or less the habit of Eastern trees. In the foot- 

 hills, the valleys, and the coast, there is less difference in time of 

 rest and of leaf and bloom. Even in regions where there may be a 

 month's difference in ripening of fruit, as, for example, in the Vaca- 

 ville district, fifty miles inland, and in Berkeley, two miles from the 

 bay shore, trees bloom almost at the same date. The difference in 

 ripening is due to the higher temperature and fuller sunshine of the 

 interior situation, which have a forcing effect, while the lower tem- 

 perature and dull skies of the summer on the coast retard maturity. 



The rest of the tree, in all save the mountain district, is not 

 dependent upon the touch of frost. It comes rather from thirst 

 than from cold. The immense weight of fruit, the vigorous growth 

 of wood, and the exhaustion of moisture from the soil by the draught 

 of the roots to compass this growth, are the chief causes which bring 

 the sere and yellow leaf in California. It is not frost, for the petunias 

 may be blooming and the tomato vines still green in the fields. But 

 the time has come for a rest. The trees sleep ; but merely as a nap 

 at midday; the early rains wake them soon. The roots are active 

 first, then the buds swell, and the blossoms burst forth sometimes 

 as early as January the almond tree first heralding the advent of 

 California's springtime. 



Sometimes this season of rest is too short for the good of the tree 

 or vine. The early rains, when followed by a spring-like temper- 

 ature, as sometimes happens, induce activity in the top as well as 

 the root, and the tree is not in condition to withstand cold weather, 

 which may follow. It is probable that such stimulated activity, 

 suddenly checked, is responsible for more ills to tree and vine than 

 are usually attributed to it. Both to insure hardiness and fruitful- 

 ness it is important that a tree shall have summer moisture enough 

 to finish its late summer and early autumn growth-processes. Refer- 

 ence to this important matter is made in the chapter on irrigation. 



