Versatile and nutritious, parsnips are being added to the menus of many restaurants. You'll love the tender carrot-like roots for their sweet and distinctive flavor that's delicious in soups and stews, mashed, stir-fried, or roasted. The trick to growing the sweetest parsnips? Wait to harvest the roots until after the first frost. Cold temperatures change the starch into sugar, making them sweet and flavorful.