The Salinas Valley shows promise of becoming a distinctive new region for growing premium wine grapes. To make the most of the cool and windy climate, however, particular irrigation management practices are required. Irrigation itself is a necessity, because annual rainfall is much lower than in the nonirrigated vineyard areas north of the San Francisco Bay, and because root depths are characteristically shallow—most of the vineyards are on old terrace soils with shallow restricting layers in the form of clay pans or abrupt stratified zones. In previous tests, we have shown that nonirrigated or minimally irrigated grapes on shallow soils in Salinas Valley are very deficient in both yield and quality compared to carefully irrigated vines.