hoop house
n.— «They hope to add a hoop house, or unheated greenhouse, later this year to extend the growing season at their farm-garden on Detroit’s east side, where they grow collards, lettuce, okra, green beans and peppers.» —“Vegetables and Concrete: Urban gardeners are turning vacant lots into profitable produce plots” by Marty Hair Detroit Free Press (Michigan) July 27, 2007. (source: Double-Tongued Dictionary)