Stemless Thistle
Onopordumacaulon

Category
Biennials

Water Requirements
Drought-tolerant; suitable for xeriscaping
Average Water Needs; Water regularly; do not overwater

Sun Exposure
Full Sun
Sun to Partial Shade

Foliage
Herbaceous

Foliage Color
Bronze

Height
under 6 in. (15 cm)
6-12 in. (15-30 cm)

Spacing
18-24 in. (45-60 cm)
24-36 in. (60-90 cm)

Hardiness
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)

Where to Grow

Danger
Plant has spines or sharp edges; use extreme caution when handling

Bloom Color
Cream/Tan

Bloom Characteristics

Bloom Size

Bloom Time
Late Spring/Early Summer

Other details
May be a noxious weed or invasive

Soil pH requirements

Patent Information
Non-patented

Propagation Methods

Seed Collecting
Allow seedheads to dry on plants; remove and collect seeds