The Grape Varieties of California

Abstract

In California grapes are grown under a wider range of climatic and soil conditions than any other cultivated crop. On one extreme are the plantings of Thompson Seedless in the desert area of southern California, where the harvest for shipment to eastern markets begins in early June. Here the elevation is from 50 to 200 feet below sea level, the average precipitation is less than 4 inches per year, and searing temperatures during the summer have been recorded above 122° F. On the other extreme, small winegrape plantings are isolated in the Sierra foothills of northern California up to 2,600 feet, where snow is present during a part of the winter and the summer climate is cool enough so that the same variety, Thompson Seedless, does not ripen until November, and then not always completely.