Gerald L. Klingaman
Plant Common Name
Astilbe, False Spirea
Astilbe is a genus of approximately 18 species native to the moist wooded areas of Asia and North America. These beautiful perennials grow from thick rhizomes (lateral underground stems) and form solid clumps of attractive compound leaves.
The ferny leaves have brownish stems which may or may not be hairy. They are compound and their leaflets are lance-shaped, oval or elliptical with coarsely toothed edges. A few odd species have simple leaves that are slightly lobed.
The primary interest comes from their feathery, plume-like clusters of blooms. The little flowers are very small with four to five petals and many thread-like stamens, which give them the feathery look. They are usually white, pink, lilac or purple and appear in summer. The fruits are capsules or follicles that dry to rich brown.
Most garden Astilbe grown today are complex hybrids that are assigned to unifying groups. Hybrids in the Japonica Group have Astilbe japonica in their parentage. The plants are compact, have glossy dark green leaves and dense flower heads and appear from early to midsummer. Those in the Crispa Group are less common but tend to be small with pink blossoms and crinkled, crisp foliage that turns bronze-red in fall. The popular Astilbe in the Arendsii Group are complex hybrids bred by George Arends. They are moderately sized, with oval to lance-shaped leaves and large pink, white or red plumes. Finally, the tall plants in the Simplicifolia Group have Astilbe simplicifolia in their parentage, offer large pyramidal plumes and tend to be slow growing.
Culture and hardiness are species dependent, however, most prefer partial shade and fertile, moist soil. Many grow in moister soils and will tolerate full sun if kept well irrigated. They require a period of winter cold for best growth and flowering, so most are not good for southern gardens. Divide their clumps every few years if they become crowded.
These low maintenance perennials are well-suited to shady gardens and look best when planted in groups or mixed with other perennials. Astilbe are often grown and harvested as cut flowers for the floral industry and their dried plumes can remain attractive through winter.
Clay, Loam, Sand
White, Red, Purple, Pink, Rose
Cutflower, Mixed Border
Sharp or Has Thorns