Plants in this genus are related to true gingers (Zingiber) and other so-called gingers (Alpinia, Hedychium), and like them have eshy rhizomes and stems bearing large leaves. In Costus, the leaves are spirally arranged around the stem. Flowers emerge from a tight, conelike cluster of colored bracts at stem ends in summer and fall.
Plants have sprawling, mounding habit. Native to the tropical forest oor, they prefer light shade but can stand full sun if roots are shaded. Use around foundation or near patio or pool; can also be grown in large pots. Plants are dormant in winter and need little water at that time. Provide a winter mulch.
C. barbatus. RED TOWER GINGER. From Costa Rica. To 68 ft. tall, 5 ft. wide. Bright green, 5- to 10-in.-long leaves have downy undersides. Flowering cone is 713 in. long, with dark red bracts and 1-in. yellow flowers; lasts for a long time on the plant. Blossoms attract hummingbirds.
C. curvibracteatus. From Central America. To 2 ft. high and 3 ft. wide. Shiny, dark green leaves grow 812 in. long. Flowering cone is 27 in. long, with 112-in., reddish orange flowers. Good container plant.
C. cuspidatus (C. igneus). FIERY COSTUS. Native to Brazil. Forms a neat clump to 12 ft. high and wide. Deep green, 4- to 7-in.-long leaves with reddish undersides. Unusual, almost cup-shaped, 3-in. orange flowers, often produced in twos or threes at stem ends. Good potted plant; attractive even when out of bloom.
C. speciosus. CREPE GINGER, MALAY GINGER. Native to the East Indies. Clusters of stems grow to 68 ft., spreading to 3 ft. Medium green, 5- to 10-in.-long leaves; 5-in.-long flowering cone with green bracts tipped red. Crepe papertextured white or pink flowers to 4 in. wide emerge from the cone two or three at a time.
C. spiralis. SPIRAL FLAG, SPIRAL GINGER. From South America. Reaches 46 ft. tall, 34 ft. wide. Glossy, bright green, 8-in. leaves. Flowering cone has orange bracts and pink-to-red, 1-in. flowers.