It is a deciduous shrub growing to a height of 2-4 m. The leaves are elliptic-acute, 6–12 cm long, with a finely hairy margin. The flowers are dark pink, with a tubular base to the corolla 15 mm long with a narrow four-lobed apex 3–4 mm across, with a strong fragrance; they are produced in slender panicles up to 15 cm long in early summer. The fruit is a dry, smooth brown capsule, splitting in two to release the two winged seeds.
Growing conditions allow for cool to temperate climate and are fully frost hardy. The plant also grows in full sun to semi shade. Despite its continental European origin, it has proved to be surprisingly successful when cultivated in the oceanic extremes of northwestern Europe on the Faroe Islands and in arctic northern Norway north to Kirkenes.