Rose Thistle

Cirsium andersonii

Native to:
United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Asteraceae
Genus:
Cirsium
Species:
Cirsium andersonii
USDA Symbol:
CIAN

Growth Characteristics

Life Cycle:
Biennial
Growth Habit:
Forb/herb
Height:
100 cm
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
jun,jul,aug,sep
Bloom Colors:
white, pink, rose

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)
Hummingbirds:
★☆☆☆☆ Documented hummingbird visits (GBIF)

Keystone Species Ranking

Pollen Specialist Bee Keystone:
★★★★☆ Native pollen specialist bee species supported by this genus (NWF)

Reported Fauna Sightings

Bees: Morrison bumble bee (Bombus morrisoni), Yellow-faced bumble bee (Bombus vosnesenskii) Hummingbirds: Rufous Hummingbird (Selasphorus rufus)

Garden & Ecology Notes

Wildlife Value:
bees, butterflies, hummingbirds, birds
Deer Resistant:
Yes
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts from root crown after fire. Found in montane areas with periodic fire regimes.

Soil Requirements

Soil Type:
rocky, well-drained, nutrient-poor soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
commonly found in mountainous regions

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
14–30 days
Notes:
Seeds germinate readily after cold stratification. Light may improve germination.

The above propagation data sourced from Claude AI