Franck Jullion, of the producers' association in the Blaye Cotes de Bordeaux appellation, said: "It's as if the vines had gone back to winter. Estates hit by frost last year will not recover. We're going to need a lot of support and solidarity."
Saint-Emilion, one of the most prestigious Bordeaux appellations, was spared, but parts of Medoc were badly hit, as were Cognac brandy producers in Charente and Charente-Maritime.
Didier Gontier, director of the Cotes de Bourg appellation, said: "This is going to affect two years of production."
Bordeaux is France's largest wine-growing area, with 300,000 acres of vineyards producing 700 million bottles, from table wines to some of the most famed and expensive vintages.