Genus: Hardheads

Centaurea

Photo/Illustration: 
Steve Aitken
Hardheads (Centaurea)
sen-TOR-ee-ah
Asteraceae
Centaurea is a large genus of about 450 species of annuals, biennials, perennials, and subshrubs from mostly dry sites, mainly in Europe and the Mediterranean. They are cultivated for their fringed flowers in shades of pink, yellow, white, and true blue. The bracts often have toothed or spiny tips in white or black. Use Centaurea in borders, rock gardens, as bedding, or for naturalizing.
Noteworthy characteristics:  Fringed flowers that are attractive to bees and butterflies. Good cut flowers.
Care:  Most species will grow in any well-drained soil in full sun and tolerate some drought. C. macrocephala and C. montana need moist soil.
Propagation: 

Sow annual seeds where they are to grow or in peat pots in spring; sow perennial seed in a cold frame in spring. Divide in spring or autumn.

Problems: 

White mold, rust, downy and powdery mildew, thread blight, Southern blight.

Species, varieties and clutivars for genus Centaurea

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
Centaurea cineraria 'Colchester White'
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
Bachelor's buttons
Centaurea cyanus
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
Giant knapweed
Centaurea macrocephala
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
Mountain bluet
Centaurea montana
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
Mountain bluet
Centaurea montana ‘Amethyst in Snow’