trefle.io · Taken Jun 14, 2022 by Diana Madrid-Jones (cc-by-sa)
Iridaceae
Rocky mountain iris
Iris missouriensis
Also known as Western blue flag, Mountain iris, Blue flag iris, Iris longipetala var. montana
Flowering Plants · Native Plants · Iris · Wildflower · Native · Blue Flowers · Meadow · Rock Garden · Western Native · Pollinator · Perennial · Mountain
Rocky Mountain iris produces stunning lavender-blue blooms in late spring and is well suited to meadow, prairie, or rock garden settings across western North America. It prefers full sun to part shade and well-drained to moist soils, making it adaptable but most vigorous when given adequate spring moisture. Divide clumps every few years to maintain vigor and encourage prolific flowering.
Growing conditions
The details behind the basics
- Daily light
- 6 hours
- Watering
- Water moderately during spring and early summer growing season; reduce significantly after flowering as the plant tolerates drie · Every 7-10 days
- Maintenance
- Moderate
- Soil
- loam
- Soil pH
- 7–8.5
- Temperature
- -25°F to 95°F
- Cycle
- Perennial
- Propagation
- Seed
Hardiness
USDA 4b-9b
Form & growth
Mature size and habit
- Mature height
- 20 ft – 40 ft
- Spread
- 20 ft
- Spacing
- 18 in apart
- Growth rate
- Fast
- Root depth
- Medium
- Flowers
- Purple
- Foliage
- Green · Medium
Ecology & origin
Where it belongs and what it brings
- Native to
- Alberta, Arizona, British Columbia, California, Colorado, Idaho, Mexico Northeast, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Utah, Washington, Wyoming
- Attracts
- Bees, Butterflies, Hummingbirds
Sources: trefle, usda
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