grape vine growing in california?

The grapes grow more so in the Napa Valley in northern California, or a bit north anyway. Although they usually like cold, I am not sure if grapes produce more than once. Good question though. I hope some Napa Valley person answers you. You could check on Napa Valley grapes or wines on line and see what comes up. You could find your answer there. It is as good to know an answer when you know where to look as information does change with time. But you can check out Napa Valley grapes and specific types on here and get a great deal of information. The growers are the experts and they will be happy to tell you more about their grapes and their vines. Vintners are people who make wines and you may locate some that way.

Are you planning competition for them? Or just curious or on a school adventure? I'm sure you can find a Napa Valley Vintner who may be happy to tell you more about your favorite grapes and wines.