Despite a record-dry month and unpredictable weather, April was a cruel month for California winemakers, bringing a series of unusually late frosts to vineyards baring the tender, green shoots of spring. The damage is still being assessed—it could be June before growers know the full extent—but most expect smaller-than-average harvests this year. The cold snap's immediate effects can be seen in some vineyards, where leaves that normally would be fluttering pale green in spring breezes are curled up brittle as December leaves. The long-term consequences are less certain.

Vines that survived the cold should produce normal fruit and quality shouldn't be affected, although growers may have to make some adjustments in how they maintain the vines, said Jim Regusci, president of Napa-based Regusci Vineyard Management. Even damaged vines may produce secondary buds that will yield fruit. The frosts hit all over Northern California, including Amador County, the Napa Valley and Sonoma County regions. Damage was spotty, a. Predictions of a small harvest come after two years of relatively normal-sized crops, which had helped to alleviate a grape glut, disappointing to growers who were hoping to get good prices. SanJoseMerc contributed. hallmark of frost, with some vineyards singed in only in a few corners. Sinking temperatures dragged growers out of bed as frost alarms on vineyard thermometers went off. Although a little frost isn't unusual, the cold snap that lasted 20 or more nights in some places was a first for many vintners. Another unknown is what the frost may have done to next year's crop—since vines are perennial, the area on the vine where buds for the 2009 harvest would form may have been damaged