Nothing would grow in the far, shady corner of my backyard until a friend suggested I try lungwort (Pulmonaria spp.). Now this oddly named groundcover, with its silver-and-white-splotched foliage, is brightening up the spot; its clusters of tiny, bell-shaped flowers—many of which change colours (usually from pink to blue) as they age—are an added bonus from mid-April to late May. Once these delicate-looking blossoms fade, lungworts continue to display attractive foliage through summer until frost.
Originating in Europe and Asia, this low-growing, deciduous perennial—a member of the borage family—is produced by slowly spreading rhizomes. Very low maintenance, it does best in partial to deep shade and grows 20 to 40 centimetres tall with a spread of 30 to 45 centimetres.
Pulmonaria species and hybrids
About a third of Pulmonaria's 14 species and many hybrids are hardy to Zone 4 or 5. The best known is Bethlehem sage (P. saccharata), which has small flowers and attractive spotted foliage. Other popular varieties include long-leafed lungwort (P. longifolia), which has long, narrow leaves with silver spots and blue flowers, and common lungwort (P. officinalis), with rough, heart-shaped, white-spotted leaves and flowers that mature from pink to blue.
Lungworts make fine companions to ferns, primroses, bleeding hearts and hostas, as well as to spring-flowering bulbs such as daffodils and tulips. The plant is also a wonderful way to add pattern and texture to woodland gardens, shady borders and pond or stream banks.
Lungwort spreads by creeping rootstalks, but isn't aggressive. It can be grown from seed in containers in spring, but hybrid varieties are considered superior to species plants and have better colour and a longer blooming period. Since lungwort doesn't come true from seed, dividing is the best method of propagation. Division should be made in late spring after blooming or in early fall. Space transplants 30 to 45 centimetres apart and provide plenty of water to help them re-establish.