These attractive, vigorous, perennial vines produce profuse, light green, fragrant flowers that are used for making beer. Hop plants also make attractive ornamentals and will quickly cover a fence arbor or wall. As with all perennial vines, Hops die back in the winter and come back in the spring. There are two types of hops used for brewing. Aroma hops are lower in alpha-acids and are used for conditioning and finishing. Bittering hops are higher in alpha-acids and are used to add bitterness. Hop plants can reach 12 ft in height in one season and can be grown where temperatures fall to minus 20°F.