If you have a rare turnip, saving seed is pretty easy. For common turnips probably not worth the space and effort. Fall planted turnips will bolt in the spring. Just let the the seed pods dry somewhat on the plants, pul the plant and let it complete drying i a sheltered space, Strip out the seeds and you are in business. In turnips will not survive the winter in your climate, Then spring planting will work. It just ties up space in the growing season.
