Lungwort is a hardy, shade-loving perennial. It is an excellent plant to grow in a moist, shady spot. Do not plant it in a spot where the soil is likely to dry out; it will not survive drought. Lungwort was used in herbal folk medicine as a gargle for a sore throat or to cleanse the digestive system. Today it is planted as a welcome addition to shade gardens. The flowers bloom in early spring.
Choose a spot in partial to full shade. The soil should be rich, friable and well drained. Do not choose a spot that is prone to dryness or where water stands after a rain.
Improve the soil. Add 2- to 4-inches of compost and 2- to 4-inches of peat moss to the surface of the soil. Incorporate by turning the soil over with a shovel. Rake the soil smooth when finished.
Plant seeds of lungwort in early spring, as soon as the soil can be worked. Sow seeds ¼ inch deep and 2- to 4-inches apart. Lightly firm the soil over the seedbed. Water well with a hand watering can, and check the seedbed daily. Water as needed to keep the soil moist but not wet. Germination should occur in 7- to 14-days.
Thin seedlings when they are 2- to 3-inches high so they stand 18- to 24-inches apart. Lungwort will rapidly increase in size and soon fill in the spaces between the plants.
Water the equivalent of 1- to 2-inches of rainfall per week. Lungwort likes a lot of water and consistently moist soil. Do not allow the plant to dry out.
Apply a light mulch of 1- to 2-inches of shredded leaves or partially decomposed compost to the soil around the plants. Keep the mulch at least 2-inches from the base of the plants; they need space and airflow around their crowns. Cover plants with a shallow, 6- to 8-inch layer of protective mulch in winter. They are hardy through USDA Zone 3 and will survive without a thick blanket of winter protection.
Dig up and divide lungwort every 4-to 5-years. This can be done immediately after they flower in spring or in late summer. Do not divide during hot weather.This plant grows best in cool weather. The chances of success when dividing lungwort are greatly improved during cool weather in early spring or late fall.
Side dress with compost in early spring. Pull back mulch, and spread a 2-inch or more layer of compost in an 8-inch circle around the base of the plant. Replace mulch.