Gardening Articles: Flowers :: Perennials
May's Flower: Bearded Iris
by National Gardening Association Editors
In the legends of the ancient Greeks, Iris -- goddess of the rainbow and a messenger of the gods -- shuttled between heaven and Earth atop colorful arcs. Wherever she stepped on earth, iris flowers sprang up in all the hues of the rainbow. To modern gardeners, these beloved flowers are, in a sense, gifts from the gods.
Of the many kinds of iris, the bearded ones, which are perfectly at home in cottage gardens and formal borders, are by far the most common.
While bearded iris are easy to grow in most regions, they show subtle preferences in climate and soil; these are worth knowing so you can enjoy them at their best. Also, because there are so many named varieties on the market, "Top Choices" (below) will help you select some of the best to grow in your garden.
As on all types of iris, the orchidlike flowers of bearded iris have six petals. The three inner ones that point up are called standards, and three outer ones that point down are called falls. The beards are the hairs that grow in the center of the falls. A healthy flowering stalk produces 9 to 12 buds on short side branches, and each flower lasts about three days over a total bloom time of about a month.
Iris are available in virtually every hue: sky blue to the deepest ocean blues, luxurious lavenders, regal purples, blazing coppers, radiant reds, saffron yellows, and soft to rosy pinks. Then there are the innumerable intricacies of color combinations, multihued beauties, contrasting beards, and other unique color patterns.
All bearded iris spread from rhizomes, roots that spread horizontally right at the soil's surface. The gray-green leaves are long, flat, and pointed, and they overlap almost like a fan.
Plants range in height from 4 inches to more than 36 inches, a habit that gives iris enthusiasts a convenient way to categorize them: dwarf (4 to 15 inches), intermediate (15 to 28 inches), and tall (more than 28 inches). The tall types, far and away the most popular, bloom in April in mild-winter regions, and as late as June in the north, but in most of the country their peak bloom is now, in May.
Most bearded iris bloom only once, but some newer introductions have the capacity to bloom a second (or third) time. Another way to maximize bloom is to use dwarf and intermediate types as well. They generally flower two to four weeks before the tall types.
Reblooming iris are extra-vigorous growers. They bloom in spring, earlier than normal, then again in summer, and, depending upon your climate, perhaps again in fall. Plants in coastal gardens can bloom continuously for 9 to 10 months, though 4 to 5 months of bloom is more typical. Most of these are tall types, while a few dwarf kinds also qualify as rebloomers.