Native Irises: The Best Low-Maintenance Irises Indigenous to the U.S.

“Irises were my first love,” says horticulturalist Kelly D. Norris, the garden author and designer known for his “new naturalism” garden style. He started out managing his family’s iris farm and eventually became a noted iris expert, writing A Guide to Bearded Irises. However, it’s not just the dizzying array of bearded irises that Norris fell hard for: He loved the beardless native irises, too. “The farm I grew up on was not far removed from native prairie remnants, including some that bordered the river. All of the little swales where they’d dug for the railroad tracks and disturbed the floodplain were home to large colonies of Iris virginica,” he remembers. On one occasion, teenage Norris took a potato fork to dig up a patch of irises in the path of development.

Indigenous irises often get less attention than their cultivated counterparts, but as gardeners aspire to plant more natives and design landscapes that better manage rainwater, American irises deserve a second look. Unlike imported irises, native irises are low-maintenance: They don’t require fertilization, and once established they will spread and come back bigger year after year. Even when not in bloom, many native irises have foliage that offers substantial architectural quality. And while we do not yet know about specific host plant relationships, they are beloved by bees, moths, and butterflies. 

Native irises, and blue flag irises in particular, are often well-suited to rain gardens and bioswales, which mimic their natural habitats near ponds and streams. Writing for the Ecological Landscape Alliance, Dr. Catherine Neal, a horticulture professor at the University of New Hampshire, noted, “Blue flag iris (Iris versicolor) is a plant that seems to be highly adapted to the lowest area of the rain garden—we have seen it survive where many other species have failed.” Norris has personally been experimenting with breeding native irises, hoping to tease out selections from wild populations that could have a little more horticultural interest in bioswales and green infrastructure. “We need a plant palette for that,” he says.

There are only 28 native iris species in the U.S. (although that number may vary slightly depending on who you talk to), but because they hybridize easily both in nature and with human assistance, there are hundreds of garden forms in cultivation. Plantsman Bob Pries, an iris hybridizer and longtime member and spokesperson for the American Iris Society, encourages gardeners interested in native irises to join Species Iris Group of North America (SIGNA). “They have a seed exchange, which is one of the easiest ways for people to get seeds of a lot of these plants,” says Pries. (Iris lovers might also explore the Society’s Iris Encyclopedia, which lists about 80,000(!) different cultivars of irises, mostly non-native, that have been registered.)

Here’s a primer on the irises native to the United States:

Blue Flag Irises