Centaurea macrocephala
Bighead knapweed, Centaurea macrocephala (often listed as Psephellus macrocephalus), is a bold perennial for sunny borders. It stands out with large yellow, thistle‑like heads in mid to late summer. Plants form sturdy, upright clumps that handle cold winters. This species is long‑lived in well‑drained soils and offers strong vertical accents for mixed plantings.
At‑a‑glance
- Group/Class: Perennial cornflower
- Height × spread: 3 to 4 ft (0.9 to 1.2 m) × 1 to 2 ft (30 to 60 cm)
- Bloom window: mid to late summer
- Color & flower form: golden yellow heads from papery brown buds
- Fragrance: 0 none
- USDA hardiness: zones 3 to 8
- Breeder / Year / Origin: unknown
- Cut‑flower notes: sturdy stems; valued by growers as a perennial cut flower
- Pet safety: unknown
How it differs
- Summer‑blooming yellow heads instead of spring blue flowers
- Taller and more architectural than most cornflowers
- Very sturdy stems suitable for cutting
- Deep‑rooted, drought‑tolerant habit once established
Strengths
- Cold‑hardy and long‑lived
- Low maintenance in average soils
- Excellent mid‑season color
- Good support for pollinators
Care in one minute
- Full sun and well‑drained soil are essential.
- Water to establish; then water deeply but infrequently.
- Avoid rich feeding; excess nitrogen leads to soft growth.
- Deadhead to control self‑sowing; divide clumps if they crowd.
- Check regional invasive‑plant guidance where applicable.
Watch‑outs
- Self‑seeds; remove spent heads if spread is a concern
- Can be locally listed or watched; verify status before planting
- May need staking in windy, exposed sites
Best uses (tags)
borders, cutting, pollinators, cottage, late season
Provenance note
Native to northeastern Türkiye through northwestern Iran; long in cultivation and widely listed by botanic gardens.
References
- RHS – Centaurea macrocephala details
- Kew Plants of the World Online – Centaurea macrocephala
- Invasive Plant Atlas – Bighead knapweed
Written by: Your Flowers Guide editorial team
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