Cornflowers Centaurea montana

Centaurea montana

The mountain bluet, Centaurea montana, is a clump‑forming perennial with fringed blue flowers. It performs best in regions with cool summers. Plants bloom in late spring and can rebloom after a hard shear. They tolerate light shade, especially in warm afternoons. This species is hardy across cold parts of North America and is reliable in ordinary, well‑drained soil.

At‑a‑glance

  • Group/Class: Perennial cornflower
  • Height × spread: 12 to 24 in (30 to 60 cm) × 12 to 18 in (30 to 45 cm)
  • Bloom window: late spring; possible light rebloom after shearing
  • Color & flower form: rich blue, fringed daisies with darker centers
  • Fragrance: 0 none
  • USDA hardiness: zones 3 to 8
  • Breeder / Year / Origin: unknown
  • Cut‑flower notes: usable in informal bouquets; cut when newly open
  • Pet safety: unknown

How it differs

  • Perennial habit rather than annual
  • Earlier season bloom than big yellow knapweeds
  • More shade‑tolerant than most cornflowers
  • Forms spreading clumps from short rhizomes

Strengths

  • Very cold‑hardy
  • Performs in average garden soils
  • Feeds pollinators in late spring
  • Can rebloom with prompt deadheading

Care in one minute

  • Site in full sun to light afternoon shade.
  • Soil: average and well‑drained; neutral to slightly alkaline is fine.
  • Water when top inch dries; avoid waterlogged sites.
  • Feed lightly in spring if growth is weak.
  • Shear after the first flush to tidy and encourage rebloom.
  • Divide every few years if clumps thin in the center.

Watch‑outs

  • Can sprawl or flop in rich soil
  • May self‑seed and spread beyond clumps
  • Foliage can look tired in midsummer heat

Best uses (tags)

borders, pollinators, cutting, cottage

Provenance note

Native to mountain regions of Europe, long grown in cottage gardens and naturalized in parts of North America.

References

Written by: Your Flowers Guide editorial team
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