Prolific perennial produces a perfect pollinator paradise! Striking blue flowers are spherical in shape and loved by bees, birds, butterflies and humans alike. From zones 3-9 this hardy perennial can grow over 90cm (3') tall and has the ability to reseed aggressively. Dead head blooms to control unwanted volunteers, collect the seed, or let nature run its course. These magnificent flowers and spiky foliage will add a layer of intrigue to your garden. Blooms early– late summer.