Achillea millefolium var. occidentalis (Western yarrow)

Formerly A. lanulosa. Rhizomatous native perennial forb with small flat flower clusters and fernlike leaves, blooming April to October. Extremely drought tolerant, though very common throughout the U.S. on wet or dry sites. Especially important in western sagebrush-Bluebunch wheatgrass (Pseudoroegneria spicata ssp. spicata) communities. Used on shrublands, prairies, mine reclamation and roadsides at all elevations; also as an ornamental and for pollinator habitat for native bees. Competitive with weeds. Smaller and much less aggressive than the non-native White yarrow (A. millefolium). Varieties listed below.




Family: Asteraceae

Duration: Perennial

Growth Habit: Forb

Native Status: Native

Growth Form: Rhizomatous

Mature Height:  36 in.

Bloom Color: White, occasionally pink

Bloom Period: Late Spring

Annual Precipitation:  6-26 in.

Drought Tolerance: High

Shade Tolerance: Medium


Wetland Indicator Status:

Fire Resistance: No

Fire Tolerance: High

Nitrogen Fixation: None


Coarse Texture: Yes

Medium Texture: Yes

Fine Texture: No

Salinity Tolerance: Low

CaCO3 Tolerance: Medium

pH Range: 6.0-8.0


Seeds per Pound: 3,400,000

Seeding Rate:  0.1-0.5 PLS lbs/acre

Season: Spring/Fall

Days to Germination:


Columbia - Source Identified selection from Sherman County and Gillman County, OR averaging 11-13 in. annual precipitation.

Eagle - Adapted to low elevation, semiarid sites with long, hot growing seasons. Easily established. Competitive with introduced grasses and annual weeds such as cheatgrass. May establish better on arid sites than other releases. (Released 2011, origin: Ada County, ID)

Yakima - Source Identified selection from Yakima County, WA averaging 6-11 in. annual precipitation. Good establishment and persistence on semiarid lands, especially locations prone to repeat disturbance such as wildfire. (Released 2004)