The food ginger from the grocery store is Zingiber official. All of the Zingibers are deciduous, so even if you protect it from cold, it will go dormant anyway. Hedychiums (butterfly gingers) and Costus (spiral gingers) are evergreen, and will freeze to the ground but come back in spring. ZIngibers, Globbas, Schomburghkias, Curcumas and Kaempferias are all deciduous.