Content Detail

Sweet iris produces beautiful, fragrant, light purplish-blue flowers with yellow beards that rise above the sharp, swordlike, blue-green leaves. The flowers bloom from late spring to early summer. In full to partial sun and well-drained, moist soils, sweet iris can be grown in cottage gardens, drought-tolerant gardens, woodlands, beds, or borders.

  • Family (English) Iris
  • Family (botanic) Iridaceae
  • Tree or plant type Perennial
  • Native locale Non-native
  • Size range Large plant (more than 24 inches)
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
  • Soil preference Moist, well-drained soil
  • Tolerances Dry sites, Occasional drought
  • Season of interest late spring, early summer
  • Flower color and fragrance Fragrant, Blue, Purple
  • Shape or form Upright
  • Growth rate Moderate
  • Wildlife Butterflies, Hummingbirds, Insect pollinators

Size and method of spreading:

At maturity, sweet iris is between 2 to 3 feet tall and 1 ½ to 2 feet wide. They spread by producing offsets from underground root structures (rhizomes) and by self-seeding. 

Native geographic location and habitat: (include C-value if appropriate)

Sweet iris is native to Europe. 

Attracts birds or pollinators: 

Sweet iris attracts hummingbirds, butterflies, moths, and bees.

Leaf description:

The leaves of sweet iris are up to 2 feet long and swordlike (lanceolate to linear). They are a medium blue-green, but variegated cultivars are available.

Flower description:

The light purplish-blue, 3- to 5-inch diameter flowers of sweet irises rise above the leaves. The flowers grow in groups of one to three at the terminal ends of the flowering stalks. Typical of iris flowers, sweet iris has three large, reflexed, petal-like sepals, or falls. Near the throat of the flower, in the center of the falls, are yellow, hairy beards. The falls are surrounding the three upright petals, or standards. Three spreading, petal-like structures (divided petaloid style) emerge from the center of the standards and cover the pollen-bearing structures (stamens). Surrounding the base of the flowers are papery, white, leaflike bracts (spathes).

Fruit description:

Sweet iris produces fruit in the form of capsules. The capsules are oblong and have three adjoining, angled sides that split at maturity to release seeds.


Plant Care:

Sweet iris can grow in more shade than other species of iris, but will perform poorly in areas with too much shade. Do not overwater; sweet iris prefers well-drained soils. Divide clumps after flowering to check for iris borers.

List of pests, diseases, and tolerances:

Insect pests of sweet iris include aphids, iris borers, and iris thrips. Sweet iris is resistant to deer and tolerant of occasional drought once established.


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