Sorbaria is a small genus of deciduous suckering shrubs in the family Rosaceae (order Rosales), comprising around four to ten species native to temperate Asia. The genus was circumscribed by Seringe ex de Candolle and formalised by Alexander Braun, with accepted authorship recorded as (Ser. ex DC.) A.Br.
The shrubs bear pinnately compound leaves that closely resemble those of Sorbus (rowan) — a resemblance reflected in the genus name. They produce large, showy terminal panicles of small white flowers in mid to late summer, carrying a sweet and lasting fragrance. Plants spread vigorously by suckers, forming dense low thickets, and can become invasive outside their native range.
The best-known species, Sorbaria sorbifolia (false spiraea), grows to about 1.8 m tall and 3 m wide at a fast rate. It is native to Siberia, northern China, Korea, and northern Japan, where it grows in sparse temperate forests at elevations of 250–1,500 m. Other accepted species include S. kirilowii, S. tomentosa (which holds the Royal Horticultural Society's Award of Garden Merit), and S. grandiflora.
Sorbaria shrubs are widely cultivated in temperate gardens for their feathery foliage, fragrant flower plumes, and tolerance of difficult conditions — including atmospheric pollution, a broad range of soil types, and partial shade. Their strong suckering habit makes them effective for erosion control, massing on slopes, and screening.
Etymology
The name Sorbaria is derived from Sorbus, the genus of rowans and whitebeams, referring to the close similarity of the pinnately compound leaves of these shrubs to those of Sorbus species. The Latin suffix -aria denotes resemblance or association with that genus.
Distribution
Sorbaria is native to temperate Asia, with species distributed across Siberia (western, eastern, and the Russian Far East), northeastern China (Heilongjiang, Jilin, Liaoning, Inner Mongolia), the Korean Peninsula, and northern Japan (Hokkaido, northern and central Honshu). Plants grow typically in sparse deciduous forests at elevations of 250–1,500 m. Sorbaria sorbifolia has naturalised as a garden escape in parts of North America, colonising waste ground and woodland margins.
Ecology
In their native range, Sorbaria shrubs occupy sparse temperate forest and forest margins at mid elevations. They tolerate a wide range of soil textures and pH levels and grow in both full sun and semi-shade. The suckering habit allows them to form low thickets that stabilise slopes. Outside their native range — particularly in North America — S. sorbifolia has escaped cultivation and naturalised in disturbed habitats, where its vigorous spread can displace native vegetation.
Cultivation
Sorbaria shrubs thrive in rich, moist soil in full sun but adapt well to most soils of reasonable quality. They tolerate dappled shade, atmospheric pollution, and a wide pH range. Protection from strong winds is beneficial. Their freely suckering nature makes them effective for erosion control, screening, and massing, but they can spread aggressively and may need containment. Flowers are produced reliably in mid to late summer and carry a persistent sweet fragrance. Sorbaria tomentosa holds the RHS Award of Garden Merit.
Propagation
Sorbaria is most easily propagated by division of suckers during the dormant season or by root cuttings taken in late winter. Seed may be sown in a cold frame as soon as it is ripe, or in late winter; seedlings are grown on under glass and planted out after the last expected frosts.
