Spacing is important any time you have a moisture loving perennial in a shade location. Space plants out about 16 to 18 inches apart to give good air circulation and to give room to grow. Lungwort spreads on rhizomes beneath the soil level. Lungwort plants grow in clumps and reach a height of about 12 inches (30.5 cm.). In proper conditions they can spread rapidly and can be divided in early spring or fall. When dividing lungworts, don't panic if the plants wilt soon after division. Simply replant them and provide water and they will perk up quickly. This beautiful shade perennial will make you dance with its impressive spring flowers and unique foliage. Starting in mid-spring shortly after Hellebores are finished booming, dainty light periwinkle blue flowers cover a low, mounded habit.