The cornflower (Centaurea ), or bachelor's button as it is sometimes known, is an old-fashioned flowering annual, beloved for its small, blue flowers. Cornflowers are attractive in both fresh and dried cut flower arrangements and add a colour not often found in the garden. Cornflowers bloom in spring and summer and are relatively care free.
Grow the cornflower in a full-sun location in the garden, unless you are in a particularly hot area of U.S. Department of Agriculture Hardiness zones 8 through 10. In that case, provide the cornflower with afternoon shade.
Water the cornflower to a depth of 6 inches and then allow the soil to dry before watering again.
Fertilise the cornflower with 10-10-10 fertiliser, at the rate suggested on the label, once a month while it is flowering. Apply the fertiliser to the soil around the plant and water it in to a depth of 6 inches.
Deadhead the cornflower periodically throughout the growing season. To do this, snap off the flower head with your fingers or pruning shears.