Get your peelers ready: Vidalia onions arrive in grocery stores Friday. A sweet onion you " can eat like an apple ," the Vidalia onion grows only in south Georgia. It's been the official state vegetable since 1990. There's even a Vidalia Onion Festival , kicking off its 41st celebration next week with a carnival, multiple cook-offs, recipe contests and a Miss Vidalia Onion Pageant.