Create Your Garden

Iris missouriensis (Rocky Mountain Iris)

Rocky Mountain Iris, Western Blue Flag, Iris longipetala, Iris missouriensis var. arizonica, Iris missouriensis var. pelogonus, Iris pariensis, Iris tolmieana

Iris missouriensis, Rocky Mountain Iris, Western Blue Flag, Iris longipetala, Iris pariensis, Iris tolmieana, Purple Flowers, Purple Iris, Violet Flowers

Quite hardy, Iris missouriensis (Rocky Mountain Iris) is a spreading rhizomatous perennial boasting large, delicate, pale blue or blue-violet flowers, 2-3 in. long (5-7 cm), with deeply veined dark purple sepals adorned with a yellow-white signal. Blooming in late spring to early summer, 1-4 blossoms per stem, they are borne atop stout stalks that arise from dense clumps of long, narrow, arching blue-green leaves. The tough leaves are avoided by cattle and deer. Commonly found growing in wet meadows, dry steppes, and open woodland in western North America, this small rhizomatous perennial tolerates some dry soils once established but only after flowering. Rocky Mountain Iris is an excellent plant for sunny perennial borders or foundations.

  • Grows up to 12-24 in. tall (30-60 cm) and 10-12 in. wide (25-30 cm). This plant will spread by rhizomes to form colonies.
  • Performs best in full sun in medium to wet, fertile, slightly acidic, well-drained soils. Some afternoon shade is welcomed in hot summer areas.
  • A welcomed addition to beds and borders, wall-side borders, city gardens, cottage gardens, and coastal gardens.
  • Remove any dying foliage in fall, old flower stems can be cut down after flowering.
  • Keep an eye out for slugs, snails, whiteflies, thrips, and gray mold. Deer resistant.
  • All parts may cause discomfort if ingested. Wear gloves and other protective equipment when handling.
  • Toxic to dogs, toxic to cats, toxic to horses.
  • Propagate by division of rhizomes from midsummer to early fall.
  • Native to North America, Mexico.

Irises: How to Grow and Care with Success


Want to learn how to grow and care for irises like a pro? Follow these simple steps and enjoy the beauty of these striking plants

Requirements

Hardiness 3 - 9
Heat Zones 1 - 9
Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Perennials
Plant Family Iridaceae
Genus Iris other species
Common names Iris
Exposure Full Sun, Partial Sun
Season of Interest Spring (Late)
Summer (Early)
Height 1' - 2'
(30cm - 60cm)
Spread 10" - 1'
(25cm - 30cm)
Spacing 12" - 20"
(30cm - 50cm)
Maintenance Low
Water Needs Average, High
Soil Type Loam
Soil pH Acid, Neutral
Soil Drainage Moist but Well-Drained, Moisture Retentive
Characteristics Showy
Native Plants United States, Pacific Northwest, Rocky Mountains, Southwest, Midwest, California, North Dakota, Nebraska, Minnesota, South Dakota, Idaho, Oregon, Washington, Nevada, Arizona, New Mexico, Wyoming, Montana, Colorado, Utah
Tolerance Deer, Wet Soil
Attracts Hummingbirds
Garden Uses Beds And Borders, Wall-Side Borders
Garden Styles City and Courtyard, Coastal Garden, Informal and Cottage
How Many Plants
Do I Need?
Guides with
Iris Species
Not sure which Iris Species to pick?
Compare Now

Alternative Plants to Consider

Iris virginica var. shrevei (Southern Blue Flag)
Iris latifolia (English Iris)
Iris lactea (Milky Iris)
Iris chrysographes (Gold-Marked Iris)
Iris macrosiphon (Long Tubed Iris)
Iris hexagona (Dixie Iris)

Recommended Companion Plants

Blechnum spicant (Hard Fern)
Cornus sericea (Red Osier Dogwood)

Find In One of Our Guides or Gardens

Native Plant Alternatives to Iris pseudacorus (Yellow Iris)
Irises: How to Grow and Care with Success
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
Buy Plants

Requirements

Hardiness 3 - 9
Heat Zones 1 - 9
Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Perennials
Plant Family Iridaceae
Genus Iris other species
Common names Iris
Exposure Full Sun, Partial Sun
Season of Interest Spring (Late)
Summer (Early)
Height 1' - 2'
(30cm - 60cm)
Spread 10" - 1'
(25cm - 30cm)
Spacing 12" - 20"
(30cm - 50cm)
Maintenance Low
Water Needs Average, High
Soil Type Loam
Soil pH Acid, Neutral
Soil Drainage Moist but Well-Drained, Moisture Retentive
Characteristics Showy
Native Plants United States, Pacific Northwest, Rocky Mountains, Southwest, Midwest, California, North Dakota, Nebraska, Minnesota, South Dakota, Idaho, Oregon, Washington, Nevada, Arizona, New Mexico, Wyoming, Montana, Colorado, Utah
Tolerance Deer, Wet Soil
Attracts Hummingbirds
Garden Uses Beds And Borders, Wall-Side Borders
Garden Styles City and Courtyard, Coastal Garden, Informal and Cottage
How Many Plants
Do I Need?
Guides with
Iris Species
Not sure which Iris Species to pick?
Compare Now

Gardening Ideas

Plant Calculator

How many Iris missouriensis (Rocky Mountain Iris) do I need for my garden?

Input your garden space dimensions

Your Shopping List

Plant Quantity
Iris missouriensis (Rocky Mountain Iris) N/A Buy Plants

Please Login to Proceed

You Have Reached The Free Limit, Please Subscribe to Proceed

Subscribe to Gardenia

To create additional collections, you must be a paid member of Gardenia
  • Add as many plants as you wish
  • Create and save up to 25 garden collections
Become a Member

Plant Added Successfully

You have Reached Your Limit

To add more plants, you must be a paid member of our site Become a Member

Update Your Credit
Card Information

Cancel

Create a New Collection

Sign Up to Our Newsletter

    You have been subscribed successfully

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Find your Hardiness Zone

    Find your Heat Zone

    Find your Climate Zone