Iris, Dutch hybrid Fleur-de-lis, Flag photo courtesy of Flower Council of Holland
Iris, Dutch hybrid
Fleur-de-lis, Flag
photo courtesy of Flower Council of Holland

This favored bulb offers a rainbow of possibility.
by Steven W. Brown, AIFD

 nothing common. Commonly known as fleur-de-lis or flag, the Iris (pronounced EYE-ris) genus comprises around 200 species, the most prevalent commercially grown of which is I. hollandica, or the Dutch hybrids. These are grown from bulbs and originate from southern Europe and the Mediterranean.

2  family ties. Irises are members of the Iridaceae family, which also includes Crocuses, Freesias and Gladioli.

3  gods and reverence. Irises take their name from the Greek goddess of the rainbow, Iris, who transported messages between mortals and Mount Olympus deities. Among her duties was leading the souls of deceased women to the Elysian Fields. In token of that faith, the Greeks planted purple Irises on the graves of women.

For centuries, the Iris (fleur-de-lis) has been revered as a religious symbol and has been used in architecture and décor.

4  a strong force. Under natural conditions, Irises bloom in the spring although modern technologies allow growers to produce cultivars that florists and consumers enjoy all year. Peak supplies are available from March through May. Most Iris varieties are produced in the United States and the Netherlands.

5  a spectrum. Irises are available in many colors, including blues, violets, whites and yellows. Most are bicolored (generally with yellow markings on the falls—the downward curving “petals”) or multicolored (with falls and standards—the upright “petals”—of different hues).

6  metric buy. Irises are sold in 10-stem bunches. Florists can purchase them in single bunches or in cases of 40 or 60 bunches. Stem length can vary depending on variety and season.

7  dry packing. Most cut Irises are shipped dry in boxes. They can be stored dry, at 32 F, for up to one week. Prolonged storage can result in failure of the blooms to open. When needed, process the Irises as described below.

8  a little tlc. It is preferable to unpack Irises immediately upon arrival. Remove foliage that will fall below the water line. Often, sand and silt are present between the foliage and stems; rinse this away thoroughly, and cut at least 1 inch off each stem end. Then dip or place the stems into a hydration solution.

Studies show that Irises may not benefit from the nutrients in standard flower-food solutions, but they do benefit from the biocides, which limit growth of harmful microbes in the water. Place Irises into properly prepared flower-food solution or into a solution specially formulated for bulb flowers. (Such solutions contain “replacement” hormones and have a lower concentration of sugar, which helps prevent leaf yellowing.) Most experts suggest using cold solutions, to reduce the chance that flowers will “blow open.” Place the flowers into a floral cooler, at 33 F to 35 F with 90 percent humidity, to hydrate for at least two hours before designing with or selling them. Frequent misting can be beneficial. Irises are not sensitive to ethylene.

9  a short life. Irises are delicate flowers and have short vase lives—only three to six days, depending on variety, source and treatments. If these flowers are handled improperly or held too long before sale, the blooms may never open. Advise consumers to keep Irises in a cool location away from drafts and excessive heat.

10  versatile powers. Historically, Iris root (orris root) was used in the treatment of certain illnesses. It also has been utilized for centuries as a fixative in perfume. Suspended in beer barrels, it keeps beer from going stale, and, in wine casks, it will enrich the bouquet of the wine. Orris root also is used to flavor brandies, soft drinks and toothpaste. information from
The American Iris Society,; Clemson University,; David Repetto, Repetto’s Greenhouse Florist, Half Moon Bay, Calif.

Steven W. Brown, AIFD, is a professor and department chair of horticulture and floristry at City College of San Francisco, with 29 years of consulting and educational experience in the floral industry. Contact him at or (415) 239-3140.