Rocky Mountain Iris
Iris missouriensis
Last reviewed: September 2026
Rocky Mountain Iris is a clump-forming forb that blooms lavender-blue from May through July. It grows well in mountain meadows and along streambanks with part sun and medium water.
Rocky Mountain Iris is toxic to dogs and cats.
Listed as toxic by the ASPCA Animal Poison Control Center (opens in new tab) (last reviewed 2026-05-21). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435and your veterinarian's emergency line.
Pollinator Patch flags toxic plants so you can choose a pet-safe native alternative for your yard.
The USDA PLANTS Database (opens in new tab) does not flag Rocky Mountain Iris as toxic to livestock.
Light
part sun
Water
medium
Size
6"–24" H × 6"–12" W
Bloom
May, Jun, Jul
Native to
AZ, CA, CO, ID and 9 more states
Pollinators
bees, butterflies
Before you buy
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Rocky Mountain iris is a native perennial with elegant blue to purple flowers that bloom from May through July. This compact iris grows 6-24 inches tall with narrow, upright foliage that creates a tidy clump in the garden.
Growing Rocky Mountain Iris
Grow Rocky Mountain Iris in part sun and medium water. Mature plants reach 6 to 24 inches tall and spread 6 to 12 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Rocky Mountain Iris is an HOA-friendly choice. Maintenance level: low. Tidiness: 4 out of 5.
Works well in: front yard, foundation, street edge, mid zone.
Wildlife value
The showy flowers attract bees and butterflies during the summer blooming period. This native iris provides important nectar sources for pollinators in late spring and early summer.
Common questions
- When does Rocky Mountain Iris bloom?
- Rocky Mountain Iris typically flowers from May through July, with timing shifting slightly depending on elevation and spring snowmelt.
- How much sun does Rocky Mountain Iris need?
- It grows best in part sun but tolerates conditions ranging from full sun to part shade, especially where soil moisture is higher.
- How much water does this plant need?
- Rocky Mountain Iris does best with medium moisture and can tolerate lower water once it is established, though it favors seasonally moist meadows and streambanks.
- What pollinators visit Rocky Mountain Iris?
- Bees and butterflies are the main visitors, drawn to the showy lavender-blue flowers during the spring and early summer bloom period.
- What kind of habitat suits this iris?
- It is often found in wet mountain meadows, along streams, and in seasonally moist grasslands at moderate to high elevations.
- Is Rocky Mountain Iris toxic to dogs?
- Yes. Rocky Mountain Iris is listed as toxic to dogs by the ASPCA Animal Poison Control Center (aspca.org). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Rocky Mountain Iris toxic to cats?
- Yes. Rocky Mountain Iris is listed as toxic to cats by the ASPCA Animal Poison Control Center (aspca.org). If your cat has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Rocky Mountain Iris toxic to livestock?
- The USDA PLANTS Database does not flag Rocky Mountain Iris as toxic to livestock.
- Is Rocky Mountain Iris HOA-friendly?
- Rocky Mountain Iris is generally an HOA-friendly choice in the right placement, with low maintenance.
These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
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