Roasted Red Kabocha Squash Winter Squash have hard, thick skins and seeds. The deep yellow to orange flesh is firmer than that of summer squash and requires longer cooking time. Winter squash varieties include: Acorn, Buttercup, Butternut, Hubbard, Kabocha, Spaghetti, and Turban. Though most varieties are available year-round, winter squash is best from early fall through