Jicama is a day-length sensitive plant, which means that the tubers are not produced until the days toward the end of the growing season are fewer than 9 hours long. These shorter days often coincide with the first frosts of fall, so you may need to provide protection to get tubers of a usable size. Greenhouses work; so do cloches and portable cold frames, which protect the foliage from the threat of frost while heating up the micro-environment around the plant itself, thus extending the season somewhat. Jicama can also be grown indoors under a light set-up. You will only be able to grow one or two plants, but it’s definitely worth the effort. Cloches can also be used at the beginning of the season to hasten the process in the early stages and to acclimate the young plants to the outdoors.