Costus (Spiral ginger, Spiral flag)

Costus Costus barbatus Photo courtesy of State of Hawaii Department of Agriculture
Costus barbatus
Photo courtesy of State of Hawaii Department of Agriculture

This exotic flower from the tropics is rooted in history.
by Steven W. Brown, AIFD

 1 dizzy spiral. Costus (pronounced “COST-us”) is commonly known as spiral ginger because its exotic foliage is arranged in ascending spirals around bamboolike stems. Some varieties have a velvety soft texture on the backs of the leaves while others are smooth with purple undersides. The bracts can be conelike or pineapple shaped.

2   family facts. The Cost-aceae family consists of four genera and more than 150 species. Costus, the largest genus, which comprises more than 100 species, is native to tropical Central and South America as well as Asia and West Africa. Related genera in the Costaceae family are Tapeinochilos (Indonesian ginger), Dimerocostus and Monocostus.

Commercial species of Costus include:

C. amazonicus

C. barbatus (red tower ginger, spiral ginger)

C. igneus (fiery Costus)

C. malortieanus (spiral flag, spiral ginger, stepladder plant)

C. spicatus, syn. C. scaber

C. speciosus (crepe ginger, wild ginger)

C. spiralis (spiral ginger)

Costus spicatus   Photo courtesy of  Fresh Flowers by Charles Marden Fitch
Costus spicatus
Photo courtesy of Fresh Flowers
by Charles Marden Fitch

3    ancient origins. In ancient times, Costus roots were used as a culinary spice and perfume. In the Kashmir region of India, Pakistan and China, Costuses are used by shawl merchants to protect their fabrics from moths. The origin of the name is derived from the Sanskrit term “kustha,” which means “that which stands in the earth.”

4    always on. Costuses are generally available all year, depending on the species and growing area, but are in heaviest production from May through July. Major commercial growing areas include Hawaii and Costa Rica.

5    basic colors. The flowers that emerge between the bracts of Costuses are red, yellow, orange, pink or white. Some species exhibit two colors in their blossoms, most often red with yellow.

6   timely selections. Cost-uses need to be harvested and chosen at their peak of maturity because they do not develop once they are cut. Look for blossoms that have high gloss and vivid color, and avoid those that are creased or marred.

7   simple care. Unpack Costuses immediately upon arrival in your shop. These flowers frequently have to be taped in their shipping containers, so carefully remove tape and any packing materials. Cut at least 1 inch off each stem, and dip or place the stems into a hydration solution. Then place the stems into properly prepared fresh-flower-food solution.

8    warmer is good. Cost-uses are sensitive to cold temperatures and should be stored at 55 F to 60 F.

9    freshen the water. Advise customers to recut stems and change the flower-food solution every other day. If proper care is administered, these blossoms will last for seven to 21 days or more.

10  design time. A long vase life and an affinity for warm temperature make Costuses a good choice for commercial designs and other arrangements that must last a long time. Their unusual shapes make them suitable focal points for contemporary designs.

some information from

The Hawaii Tropical Flower Council,; Plants of Hawaii;  World Wide Words, www.worldwide; and Aloha Tropicals,

Steven W. Brown, AIFD, is a professor and department chair of horticulture and floristry at City College of San Francisco, with 28 years of consulting and educational experience in the floral industry. Contact him at or (415) 239-3140.