Centaurea
(Perennial cornflower or Knapweed) I love these free-flowering, clump-forming plants, which can be divided into two groups: tall and upright ones with large, knob-like flowers and short, mounding types with flat, wheel-like flowers.
Left to right: Centaurea dealbata 'Steenbergii', Centaurea montana 'Purple Heart', Centaurea atropurpurea, Centaurea 'Jordy'
Centaurea Flowers & Plant Shape
In my garden the shorter types form the backbone of the mid-spring border. All have flowers that emerge from a distinctive boss of scaly, papery bracts, and the foliage is also very handsome.
Left to right: Centaurea montana 'Sulphurea', Centaurea macrocephala, Centaurea 'Caramia', Centaurea montana 'Parham
Centaureas Are Great For
Most Centaurea are short and therefore great for the front of the border. Just one is suitable for the back and that is Centaurea macrocephala. Bees and butterflies love these plants. They are also suitable for cutting.
How To Care For Centaureas
Centaurea love a well-drained soil that does not dry out, in sun or partial shade. Remove the old stems of shorter Centuaurea to discourge the plant from seeding around and to promote new flowers. Cutting back the whole clump will encourage tidier growth and help to prevent mildew from taking hold later in the season.
Centaureas Are Great with
Anything 'cottagey' including Achillea, Campanula and Salvia
Centaurea montana 'Carnea' with Euphorbia polychroma and the leaves of Bergenia 'Beethoven'
Centaurea montana with Aquilegia vulgaris 'Alba', pink Chaerophyllum hirsutum 'Roseum'
Centuarea montana purple form with blue Brunnera macrophylla 'Hadspen Cream' and purple flowers of Symphytum officinalis
