Mature winter squash will have a hard rind that cannot be easily sliced with your fingernail and the color will be deeper. To harvest, cut the squash away from the vine leaving about two-inches of stem attached to the fruit. Handle the squash with care to avoid damaging the rind. Any winter squash that has a damaged rind or is harvested without a stem attached will not store well and should be used soon after harvest.
Winter squash should be stored in a cool, dry area. For the best air flow and to prevent rot, store in a single layer and avoid allowing the fruit to touch. (Cynthia Domenghini)