Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Cirsium (SIR-see-um) (Info)
Species: altissimum (al-TISS-ih-mum) (Info)
Synonym:Carduus altissimus
Synonym:Cirsium altissimum var. biltmoreanum
 One member has or wants this plant for trade.
Category:
Biennials
Perennials
Height:
36-48 in. (90-120 cm)
4-6 ft. (1.2-1.8 m)
6-8 ft. (1.8-2.4 m)
Spacing:
36-48 in. (90-120 cm)
Hardiness:
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)
Sun Exposure:
Full Sun
Danger:
Plant has spines or sharp edges; use extreme caution when handling
Bloom Color:
Violet/Lavender
Bloom Time:
Late Summer/Early Fall
Mid Fall
Foliage:
Herbaceous
Other details:
May be a noxious weed or invasive
This plant is attractive to bees, butterflies and/or birds
Drought-tolerant; suitable for xeriscaping
Average Water Needs; Water regularly; do not overwater
Self-sows freely; deadhead if you do not want volunteer seedlings next season
This plant is resistant to deer
Soil pH requirements:
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)
Patent Information:
Unknown - Tell us
Propagation Methods:
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; sow indoors before last frost
Seed Collecting:
Allow seedheads to dry on plants; remove and collect seeds
Properly cleaned, seed can be successfully stored
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