I store the turnips in a bushel basket in a cool dark room. Once picked, do not wash them. I bush the soil off and take them inside. Cut the greens off, I'm sure to leave a solid 2-3" of stem on them as well as the main tap root. I have found this helps keep the turnips from spoiling. Gently place them in a basket/box. Do not drop them onto each other, and don't pack too tight. Stored this way, they will last easily 3-4 months, we've even kept them as long as 6 months this way.