Plant Data Sheet





Tim Haden








Species: Indian thistle, edible thistle, Cirsium edule


Range: Cascades to Coast in Washington to Central British Columbia and S. Alaska. It is hardy to zone 7.

Climate, elevation: Moist climate,30 to 2100 meters, average 784




Local occurrence: Counties in Washington State




Habitat preferences: Moist meadows, clearings, forest openings usually at middle to high elevations, Moist to mesic meadows, avalanche tracks and open forests in the upper montane to lower alpine zones. Slope gradient 18 56 degrees


Plant strategy type: Colonizer, It is monocarpic, growing as a low rosette of leaves for a number of years, then sending up the tall flowering stem in spring, with the plant dying after seed maturation.


Associated species: Bull thistle, non-native or Canadian thistle, non-native


May be collected as: Seeds and are 4-5 mm long, with a downy pappus which assists in wind dispersal..


Collection restrictions or guidelines: Mature inflorescences are brown and pappus is silver and begins to fluff out. Collect early to avoid seed predation by weevils. A monocarpic species, it grows for a number of years without flowering but then dies after flowering.





Seed germination: Germination usually takes place within 2 - 8 weeks at 20c. 5 month outdoor cold moist stratification also an alternative.
Seedlings are transplanted 14 days after germination to individual containers containing standard potting mix of peat moss, fir bark, perlite, and sand.
Sow early spring or autumn.

Seed life: Collect mature achenes when mid September when they turn gray in color and are easily separated from the receptacle. Seeds are pulled from heads and rubbed over a screen to remove the pappus.

Recommended seed storage conditions: Seeds are collected in paper bags and kept in a well ventilated drying shed prior to cleaning.


Propagation recommendations: Seeds, it is in flower from July to August, and the seeds ripen from August to September, sow in early spring or autumn in greenhouse if possible. Transplant germinants. Water with mist, but leaves rot easily so do not over water.

Soil or medium requirements : prefers light (sandy), medium (loamy) and heavy (clay) soils, prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires moist soil, SMR 4 7 (range 1-8).

Installation form: Seed or germinant. An easily grown plant, succeeding in any ordinary garden soil in a sunny position, germination rate 50%.


 Recommended planting density: not available


Care requirements after installed: Water weekly, needs moist soil, fertilize with Nutricote (NPK 13-13-13) 3 months after transplanting. Be careful not to over fertilize; lush foliar growth attracts aphids.


 Normal rate of growth or spread; lifespan: Perennial growing to 2m, grows in colonies, 3-4 years, dies after flowering.




Sources cited:

1.Washington Native Plant Society:

2. E-Flora BC: Electronic Atlas of the Plants of British Columbia


4. Native Seed Network:

 5. Plants for a Future:


Data compiled by:

Maura Shelton May 25, 2006