[Illustration: PLATE I.--Two views of vineyards in California. _Top_, a vineyard in the orchard region of central California; _bottom_, a vineyard in southern California.] CHAPTER II GRAPE REGIONS AND THEIR DETERMINANTS Happily, the grape in its great diversity of forms accommodates itself to many conditions, so that some variety of the several cultivated species will produce fruit for home use, if not as a market commodity, in every part of America adapted to general agriculture. But commercial grape-growing on this continent is confined to a few regions, in each of which it is profitable only in ideal situations. In fact, few other agricultural industries are more definitely determined by environment than the grape-industry. Where are the grape regions of America? What determines the suitability of a region for grape-growing? Answers to these questions furnish clews to the culture of this fruit and help in estimating the potentialities of a new region or of a location for grape-growing. THE GRAPE REGIONS OF AMERICA There are four chief grape-growing regions in North America, with possibly twice as many more subsidiary ones. These several regions, each of which has its distinct varieties and to less extent distinct species, and in each of which grapes are grown for somewhat widely different purposes, give a great variety of industrial conditions to the grape-growing of the continent. Nevertheless, the regions have much in common in their environment. It is from their differences and similarities that most can be learned in the brief discussions of the regions that follow. _The Pacific slope._ The Pacific slope takes precedence among the grape regions of the continent, exceeding all others combined in the production of grapes and grape products. California is the viticultural center of this great region, grapes being grown within her bounds from the foot of Mount Shasta on the north to Mexico on the south and from the foothills of the Sierras on the east to the forest that borders the coast on the west. So outlined, California might appear to be one vast vineyard, but it is only in favored valleys, plains and low hills in the territory bounded that the vine is sufficiently well suited to be productive. Outliers of this main region of the Pacific slope run north into Oregon, Washington, Idaho and even into British Columbia, forced more and more eastward the farther north to escape humidity from the ocean which northward passes farther and farther inland. Other outliers of the main region are found eastward in Nevada, Arizona, New Mexico and even Utah and Colorado, though for the most part in these states grape-growing is still insignificant. Plate I shows typical vineyards in California.