These handsome perennials form strong clumps, the erect stems carrying gigantic umbels of cobalt-blue flowers. 20-30 cm across. They like a sunny situation and well drained soil. Plants may be propagated by division in spring. They are hardy in most areas, dying back to bulb form in winter. Ideal for containers on patios or outdoor areas. Require ample water during the growing season, but must not become waterlogged in winter.