Mertensia

These hardy perennials are natives to North America and Japan. They grow from 12 to 24 inches high and bear clusters of bell-shaped flowers. M. pulmonarioides (Bluebells/Virginian Cowslip) is a plant with oval, blue green leaves that die by mid-summer. The tubular-bell-shaped, deep blue flowers hang in clusters in the leaf axils, in the spring. M. simplicissima has succulent, light blue-gray leaves that are round to spoon-shaped. In early summer, small, blue flowers are borne atop low stems.

Pot Cultivation

M. simplicissima needs sharply drained, sandy soil with grit or sand added. It should be planted in a position with full sun and shelter from dry winds to avoid scorching the tender foliage. M. pulmonarioides should have moist, but well-drained, humus-rich soil. This variety is susceptible to slug damage.

Propagation

These plants may be propagated by division in the spring or by sowing seeds in pans of finely sifted sandy, peaty soil, in the fall. Cover the seeds lightly with the fine soil and moisten by immersing the pans in a pail of water so that the water is soaked up. Place them in a cold frame and cover with glass panes. When they sprout, remove the glass and expose the seedlings to light. When they are large enough, they may be transplanted to their permanent positions.