Plant Data Sheet


Species (common name, Latin name)

Bigflower agoseris, Agoseris grandiflora


Large Photo of Agoseris grandiflora

            ©Gary A. Monroe. Ball Canyon, Sierra Co., CA. June 14, 2003.



Washington, north and central Idaho, Oregon and California


Climate, elevation

Low elevation


Local occurrence

Pullman area


Habitat preferences

Open places such as meadows and praries.


Plant strategy type/successional stage (stress-tolerator, competitor, weedy/colonizer, seral, late successional)

Forb/herb. National Wetland Indicator. Low-growing grass.


Associated species


May be collected as: (seed, layered, divisions, etc.)

Seeds are collected by cutting the inflorescence after the pappus has expanded. Seed is wind disseminated and shatters soon after ripening.


Seed germination (needs dormancy breaking?)

Wind disseminated. Usually breaks once ripe. No cold stratification required.


Seed life and Recommended Seed Storage Conditions

Seed is stored in paper bags at room temperature until cleaned. For small amounts, the pappus can be removed by hand. With larger amounts, a hammermill is effective for removing the pappus. Seed is then cleaned with an air column separator or air screen equipment. Cleaned seed is stored in controlled conditions at 40 degrees F. and 40% relative humidity.



Propagation recommendations (plant seeds, vegetative parts, cuttings, etc.)

Seeds are sown in January.


Soil or medium requirements (inoculum necessary?)

Adapted to fine, medium and course textured soils. Anaerobic tolerance is low. pH between 5.8 and 7.3. Medium moisture use. Minimum 8 inch root depth.


Installation form (form, potential for successful outcomes, cost)

273,665 seeds per pound. Moderate spread rate. Medium seed vigor.


Care requirements after installed (water weekly, water once etc.)

Plants should be watered deeply every other day.


Normal rate of growth or spread; lifespan

Plants develop quickly after germination and the active growth phase is around 60 days.


Sources cited

1.      USDA – NRCS:

2.      USDA – NRCS, VegSpec:

Data compiled by Robert Franco 5/27/06