Sicilian Starthistle, Sulphur Knapweed
Centaureasulphurea

Category
Annuals
Biennials

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

Sun Exposure
Full Sun

Foliage
Herbaceous

Foliage Color

Height
24-36 in. (60-90 cm)
36-48 in. (90-120 cm)

Spacing

Hardiness
Not Applicable

Where to Grow

Danger

Bloom Color
Pale Yellow

Bloom Characteristics

Bloom Size

Bloom Time
Late Spring/Early Summer
Mid Summer

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)

Patent Information

Propagation Methods
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
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
N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed