Pulmonaria 'Cotton Cool'
Common Name: lungwort
Type: Herbaceous perennial
Family: Boraginaceae
Zone: 4 to 9
Height: 0.75 to 1.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: April
Bloom Description: Blue
Sun: Part shade to full shade
Water: Medium
Maintenance: Low
Suggested Use: Ground Cover, Naturalize
Flower: Showy
Leaf: Colorful
Tolerate: Deer, Heavy Shade, Black Walnut

Culture

Easily grown in average, medium moisture, well-drained soils in part shade to full shade. Prefers cool, organically rich, humusy soils that are kept consistently moist. Soils must not be allowed to dry out. Plants may go into dormancy in the heat of a St. Louis summer if soils become too dry. Foliage may depreciate considerably in hot summer weather and may scorch if grown in too much sun. Although plants tolerate light morning sun, they need afternoon shade. Remove flower stems immediately after bloom. Plants spread slowly by creeping roots. Divide plants in fall if they become too crowded. Plant leaves may retain some color in warm winters.

Noteworthy Characteristics

Pulmonaria is a genus of about 17 species of deciduous or evergreen herbaceous perennials from Europe and Asia. Lungworts are shade plants that, like many of the hostas, are often valued more for their attractive foliage than for their spring flowers.

Genus name comes from the Latin pulmo meaning lung. In accordance with the Doctrine of Signatures, genus plants were once believed by Medieval herbalists to be an effective remedy for treating lung diseases because the spotted plant leaves purportedly resembled diseased lungs. It is, however, well established today that there is no valid basis for believing genus plants have any value as medicinal plants.

Common name of lungwort is in reference to the supposed resemblance of the blotched/spotted leaves to a diseased lung.

‘Cotton Cool’ is a mounding variety that features silver leaves with white blotching and blue flowers. It typically grows in a basal clump to 12” tall and spreads to 19” wide. Ovate to elliptic, silvery leaves have white blotching. Drooping clusters (terminal cymes) of funnel-shaped flowers appear on short stalks just above the foliage in spring. Flowers emerge pink but mature to blue, with pink and blue flowers often simultaneously present on blooming plants.

Problems

No serious insect or disease problems. Slugs and snails are occasional insect pests. Powdery mildew can be a significant problem on some lungworts, particularly if soils are allowed to dry in summer. Leaves can depreciate considerably in extremely hot weather and/or too much sun (scorch).

‘Cotton Cool’ reportedly has good resistance to powdery mildew.

Garden Uses

Excellent foliage plant for shady areas of the landscape. Spring flowers are also attractive. Best grown in groups or massed as a ground cover. Best in woodland or shade gardens, shaded border areas or shaded areas of rock gardens. Also can be an effective edging plant for shady paths.