This year is being observed as the Year of Centaurea by the National Garden Bureau. Decades ago, bachelors sported the flower when they went courting. Annual bachelor's-buttons and basketflowers begin to bloom in late spring and perform throughout summer. Many varieties are hardy to Zone 4, although mountain bluet is hardy to Zone 3. Dusty miller is a member of the Centaurea genus and is grown for its foliage, not flowers.
Most people treat it as an annual, even though it is classed as a perennial.
It looks bedraggled after going through winter. Surprisingly knapweed and hurt sickle are noxious weeds in the same family. Basketflower can reach 4 feet in height. The shape of the flower petals resembles thistle but they're not prickly. Centaurea is easy to grow from seeds sown in early spring, as soon as the ground can be worked.