Iris douglasiana

Common Names

Douglas Iris, Mountain Iris, Western Iris, Pacific Coast Iris

Summary

Douglas iris is an evergreen, rhizomatous perennial native to the Pacific coast from southern Oregon to central California. It forms clumps with sword-shaped dark green leaves and branched flowering stems bearing blue to purple, lavender, or cream flowers with purple, blue, or gold veins and a signal patch at the base of the falls; plants reach about 1–2 ft tall and 2–4 ft wide, forming large colonies.

Preferring full sun to partial shade on well-drained soils, this drought-tolerant plant performs best with winter moisture and reduced summer watering where rainfall is seasonal. It can be propagated by seed or division and should be divided every 3–5 years. Deer resistant and attractive to pollinators, it suits ground covers, borders, rock gardens, and meadow plantings in hardiness zones 6–9.

Lifecycle

Perennial

Height

1-2 feet

Spread

2-4 ft

Hardiness Zones

Zones 6-9

Sunlight Requirements

Ideally full sun to partial shade.

Soil Type

Well-draining loam soil, pH slightly acidic to neutral.

Soil Drainage

Well-drained soil; avoid waterlogging.

Soil pH

5.0-8.0

Bloom Color

Blue to purple, with occasional cream, white, lavender, or yellow variations.

Bloom Time

Spring

Foliage Color

Green, with variations from yellow-green to dark green.

Fall Foliage Color

No fall color change

Leaf Lifecycle

Evergreen broadleaf

Growth Rate

Moderate

Seasons of Interest

Spring, Summer, Fall, Winter

Propagation Methods

Seeds and Division

Attracts Wildlife

Attracts bees, hummingbirds, butterflies, other pollinators, birds