Valley Climate. 15 
has recently become prevalent on deciduous fruit trees in some 
regions. Directly under coast influences, moss and lichens 
gather quickly, and should be removed. Spraying with alkaline 
washes not only kills insects but cleans the bark from parasitic 
vegetable growth. Although fruit trees on the coast are not 
so subject to sunburn as in the interior, there is especial value 
in low heading to withstand winds; there should also be plenty 
of room given the trees, that sunshine may have free access to 
warm the ground all around the tree. 
VALLEY CLIMATE. 
The characteristics of the interior valley climate are higher 
summer and lower winter temperatures than on the coast, the 
range of temperature being very nearly the same both north and 
south; rainfall abundant in the north and decreasing rapidly 
southward, so that as a rule the interior valleys in the south half 
of the State require irrigation; very dry air and almost constant 
sunshine, freedom from fogs and from dew in summer-time; 
winds occasionally strong, hot, and desiccating in summer and 
cold in winter. 
Local Modifications —The term “valley climate” is broad, 
and includes everything, from the coast to a certain elevation on 
the slope of the mountains. Certain small valleys protected 
from cold northerly winds and from fog-bearing westerly winds 
and open to the spring sunshine, have a forcing climate which 
produces the earliest maturing fruit of the season; earlier not 
only than the coast and the mountain but also somewhat earlier 
than adjacent locations in the broad, open valley. Slight ele- 
vation, even on the sides of small valleys, frequently secures 
freedom from winter frosts and ministers to early ripening. 
Elevation above sea-level on the rims of great valleys also secures 
similar results and gives rise to thermal belts in which semi- 
tropical fruits are successfully growing even as far north as Shasta 
County. On the floors of great valleys moderating influences 
are secured on the lee side of wide rivers and by planting on the 
river bank or on slightly elevated swells rather than on the level, 
open plain. The river bottom lands of the great valleys, though 
subject to severe frosts, are freer from the effects of desiccating 
winds than the open plains; they are, however, more favorable 
to the spread of certain blights than the plains are. 
Some of the horticultural effects of valley conditions are as 
follows: Early ripening and perfection of summer and autumn 
fruits, owing to continual sunshine and dry air; forced maturity 
of certain late fruits, as apples and pears, which destrovs char- 
acter and keeping quality; injury from sunburn and hot winds 
