Viticulture depends on such factors as sunlight, soil, moisture, wind, and pest and disease control. The best wines result from warm, dry conditions. Grape vines can be transplanted from established vineyards, or propagated from cuttings of new growth with two or three buds. Two thirds of the grape vines in the United States grow in California, mostly in the San Francisco Bay area, supplying the bulk of the grapes for the expansion of the American wine industry since 1950. Washington and New York rank next among the 13 grape-growing states.
Phylloxera, a North American insect that kills the vine by feeding on the root, was not identified until the late 19th cent. It caused the failure of early plantings of European grapes in the E United States and, beginning about 1860, spread around the world, probably traveling on resistant American vines, infecting V. vinifera from France to Australia to California. French and American researchers finally saved the world's wine industry by grafting phylloxera-susceptible European vines onto resistant E American roots. Virtually all wine grapevines in Europe and California are grafted to rootstocks of E American origin. In 1979 phylloxera B overcame the resistance of the dominant rootstock in Northern California vineyards; thousands of acres subsequently were replanted with more resistant rootstocks.
Besides phylloxera, the V. vinifera of the Pacific slope is harassed by a variety of pests and diseases, including black measles, little-leaf, nematodes, red spiders, rabbits, and gophers. Among the afflictions of vineyards in the E United States are mildew, a devastating fungal disease; the grape-berry moth, which destroys fruit by causing it to color prematurely; the grapevine beetle, which eats the new buds in spring; climbing cutworms, which hide in the ground during the day and feed on the buds at night; black rot, which shrivels the fruit; and crown rot, which destroys the vines of some varieties.
Prophylaxis of healthy vines and treatment of afflicted ones are but two of the intensive, continuous aspects of viticulture. From the early stages of tending a vineyard, when appropriate vines must be selected and congenial soil chosen for them, through the operations of cutting, layering, grafting, planting, and fertilizing, up to the gathering of the crop, the grower must apply equal measures of skill, knowledge, and industry.
Vineyards are believed to have been introduced to Europe by the Phocaeans c.600 B.C. References by Homer and Vergil and in the Bible confirm that viticulture was widespread in the Mediterranean region in antiquity. Large areas of France, Italy, the Rhineland, Spain, and Portugal eventually proved hospitable to V. vinifera, which also flourished in Greece, North Africa, the Canary Islands, and the Azores. In A.D. 81 Emperor Domitian, fearing grain scarcity, restricted the spread of vineyards in Italy. The Romans also carried the vine to England, where its cultivation was attempted sporadically until the 19th cent. with scant success. Repeated attempts to transplant grapes to the New World began early in the 17th cent. but Tuscan vine growers in Virginia (working for Thomas Jefferson) and German immigrants from the Rhineland to Pennsylvania failed. Grape growing did not succeed in the early United States until the introduction of commercial varieties—the Catawba in 1830 and the Concord in 1849—of phylloxera-resistant species native to the E United States.
There were 3,267 households out of which 50.0% had children under the age of 18 living with them, 69.1% were married couples living together, 9.7% had a female householder with no husband present, and 16.4% were non-families. 11.9% of all households were made up of individuals and 1.9% had someone living alone who was 65 years of age or older. The average household size was 3.07 and the average family size was 3.33.
In the CDP the population was spread out with 32.5% under the age of 18, 5.3% from 18 to 24, 36.8% from 25 to 44, 19.5% from 45 to 64, and 5.9% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 99.0 males. For every 100 females age 18 and over, there were 91.8 males.
The median income for a household in the CDP was $65,192, and the median income for a family was $66,929. Males had a median income of $43,877 versus $37,195 for females. The per capita income for the CDP was $24,178. About 2.1% of families and 3.2% of the population were below the poverty line, including 3.6% of those under age 18 and 2.4% of those age 65 or over.