These remarkably cold-hardy Asian perennials have a year-round presence in the garden, beginning with spring flowers and then growing into welcome clumps of foliage. Cut back in early spring before the flush of new growth to renew the planting.
D. aspersa. This leathery-leaved perennial grows about 15 in. tall and can spread to 3 ft. even in deep shade. White-to-pale yellow flowers with dark freckles have the fragrance of lemons.
D. pernyi. Zones US, MS, LS, CS; USDA 6-9. Upright, 10-in.-tall stems bear flowers in spring from the axils of the glossy leaves, making a row of white bells hanging along the stem.
D. undulata. Low growing to 46 in., featuring white, bell-shaped blooms with freckles, followed by purple fruit.