Centaurea (pronounced cen-TAR-ee-ah) is also known as knapweed, cornflowers, bachelor's buttons or basket flowers and you may have even heard your Grandma or Great Grandma call them blue-bottles. The plants are drought-tolerant and do best with infrequent watering. Deadheading will encourage more prolific blooming. All of our Centaurea Plants for sale are shipped with very well-established root systems. We guarantee them to arrive alive and thriving.