Purple bearded iris
Rain drops glisten on this classic, velvety-purple bearded iris.
George Weigel

The iris – that flamboyant perennial flower with the flag-like blooms – has been revered since it earned the namesake of the Greek Goddess of the Rainbow.

It’s become a symbol of royalty, the official flower of the 25th wedding anniversary, the state flower of Tennessee, and a favorite painting subject of artists from Van Gogh to Monet. Greeks planted irises by graves to attract the Goddess Iris, who would deliver souls via rainbow to Heaven.

Irises are widely planted from Canada to Florida for their heavenly big blooms that come in a rainbow of colors, including velvety purple, royal blue, lavender, pink, white, red and yellow.

Siberian iris
Siberian iris has grass-like foliage and does well in rain gardens.
George Weigel

Beards and Clean-shaven

  • The most common iris is the German bearded iris (Iris germanica) – a 2- to 3-foot-tall plant with bladed leaves and mid-spring flowers that have an upright center (the “standard”) and drooping petals around the perimeter (the “falls”). The front has a little fuzzy pad (the “beard”) that makes a soft and steady landing zone for pollinating bees.
  • Siberian iris (Iris siberica) doesn’t have a beard but does have finer, more grass-like leaves and long-lasting spring flowers, most commonly in blue, lavender or purple.
  • Species of Louisiana and Japanese irises also are beardless and prefer damp sites, including partly shaded ones. They’ll even grow in water gardens.
Crested iris
Crested iris is a short, native type of iris that colonizes in shade.
George Weigel
  • Crested iris (Iris cristata) is a 4- to 6-inch tall dwarf, U.S. native iris that spreads to form a dense colony, ideally in a shaded rock garden or woodland garden. It flowers bluish-lavender in early spring.
  • And rock garden iris (Iris reticulata) blooms even earlier – sometimes through the melting snow in late winter. Flowers are 4 to 6 inches tall and come in purple, yellow or blue.

Growing Iris

  • Best planting sites vary by iris type. Bearded and rock-garden irises are happy in sun, Siberian and Louisiana irises prefer damp sites, and crested iris prefers shade.
  • Cut off flower stalks after bloom. All foliage can be clipped to a stub when it browns or runs into an attack by its main nemesis, the iris borer.
  • Fertilize iris in early spring and again in early summer with a balanced, organic-rich fertilizer. Plants can be divided any time after bloom up until six weeks before fall’s first expected frost.