Classified as a "Chinese cabbage" along with bok choy, Chinese broccoli, and a host of other green veggies, Napa cabbage differs in that its harvest generally occurs in the spring and summer. With its distinctive oblong shape and frilly leaves surrounding sweet, bright white stems, this type of cabbage lends itself well to salads or quick cooking dishes such as stir-fries. The cabbage should feel tight and firm and not have too many blemishes, although you can peel off the outer leaves if they've been damaged in transport.