Cenaurea Montana are usually perennials, but can also be annuals and even shrubs.  With distinct furry leaves the plant is very hardy, almost indestructable. Another that needs very little care throughout the year. 

Plant late spring for a summer show, like all flowers, dead head to prolong the flowering time. Once the flowers have finished I cut the plant to the ground, usually this encourages it to sprout more flowers late in the summer. At the end of the season, again cut the plant to the ground ready for next season. Montana can be invasive if not controlled, it will seed and spread if your not careful. but this is noi reason not to have it in the garden. Its blooms are neautiful and well worth the effort once it starts flowering.