Centaurea Species, Golden Star Thistle, St. Barnaby's Thistle, Yellow Cockspur, Yellow Starthistle
Centaureasolstitialis

Category
Annuals
Biennials

Water Requirements
Average Water Needs; Water regularly; do not overwater

Sun Exposure
Full Sun

Foliage
Herbaceous

Foliage Color

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
Not Applicable

Where to Grow

Danger
Parts of plant are poisonous if ingested
Plant has spines or sharp edges; use extreme caution when handling

Bloom Color
Gold (yellow-orange)

Bloom Characteristics
This plant is attractive to bees, butterflies and/or birds

Bloom Size

Bloom Time
Mid Summer
Late Summer/Early Fall
Mid Fall

Other details
May be a noxious weed or invasive

Soil pH requirements
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)
7.9 to 8.5 (alkaline)

Patent Information

Propagation Methods
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; stratify if sowing indoors
From seed; direct sow after last frost
Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting
Allow seedheads to dry on plants; remove and collect seeds
Properly cleaned, seed can be successfully stored