An annual plant that also answers to Cornflower, Bachelor’s Button, Bluebottle, Hurtsickle, Hardheads, Knapweed, and Star Thistle. We use the genus name to keep it nice and simple. Grows well in any ordinary, well drained garden soil. Seeds will flourish within the pH range of 5.5-7.0. Deadhead regularly to prolong blooming. You will find planting several times over the spring will produce a longer bloom time throughout summer and early fall.
Latin
Centaurea cyanus
Family: Asteraceae
Difficulty
Easy
Season & Zone
Exposure: Full sun
Zone: 1-10
Timing
Direct sow starting just before last frost, and again every two weeks until end of May. Can be direct sown in autumn as well. Starting indoors is not necessary, but can be accomplished by keeping seed trays in the dark at the optimal soil temperature of 15-21°C (60-70°F). Move under bright lights once germination occurs, and transplant out in late spring, around mid-May.
Starting
Just cover the small seeds. Thin or space to 15-30cm (6-12″) apart.