Centaurea (Bachelor's Button)
Centaurea is a clump-forming plant with gray-green lance-shaped leaves. The flower buds, resembling tiny pineapples, open into exotic flowers with long blue petals with a lacy texture, around reddish-purple centers. Centaurea will do well in almost any well-draining soil in a sunny location. Little care is required, though you may need to remove volunteer seedlings or divide the plant every few years to prevent it from spreading. Deadhead after flowering to encourage reblooming in late summer, although the second blooming typically won't be as vigorous as the first one. Some gardeners like to prune them back quite hard mid-summer to rejuvenate the entire clump with new foliage.