Valued for light, airy quality of plumelike flower clusters and attractive foliage and for ability to provide color from late spring through summer. Leaves are typically divided, with toothed or cut leaflets, though in some species they are simply lobed, with cut margins. Small white, pink, or red flowers are carried in graceful, branching, feathery plumes held on slender, wiry stems ranging from 6 in. to 3 ft. or taller. Most plants grow 2–3 ft.wide.
Astilbes are the mainstay of the shady perennial border, although in cool-summer climates they can withstand full sun if watered adequately. Effective at the edge of pools, along shady paths, in containers. Need moist (but not boggy), rich soil with ample humus. Cut off faded flowering stems and divide clumps every 4 or 5 years. Survival in coldest areas (Zones 1a, 1b, 2a) depends on good snow cover.
Blooms in late summer, grows taller than A. x arendsii, and tolerates dryness a little better. Varieties include a range of sizes and flower colors.
Low mats of leaves are topped by lilac-pink flower clusters that rise to 12–15 in. high.
Bright pinkish purple flowers in spikelike clusters that grow to 4–5 ft. tall.
Grows to about 18 in. high and wide. Leaves are merely cut or lobed, not divided into leaflets. Better known than the species are it garden varieties and hybrids. ‘Pink Lightning’ has delicate blooms that emerge purplish red and open to clear pink. ‘Sprite’ (the best known) is a low-growing, compact plant that blooms profusely in summer, bearing drooping pink, 1-ft. spires above bronze-tinted foliage. ‘Hennie Graafland’ is similar but grows a few inches taller and blooms a little earlier.
Most astilbes sold belong to this hybrid group or are sold as such. Parentage is complex, but plants often have A. japonica, A. chinensis, and/or A. thunbergii in their ancestry. The plants differ chiefly in technical details. All can take full sun only in cooler climates. Short-lived in Zones 8, 9, 18–24. The following are some of the best varieties.
‘Bridal Veil’: Midseason to late. Full white plumes to 3 ft. tall.
‘Color Flash Lime’: Midseason. Pink flowers rise about 2 ft. above light green foliage that picks up bright yellow tones.
‘Color Flash’: Midseason. Pink flowers rise about 2 ft. above colorful foliage. Leaves gradually turn from green to burgundy.
‘Deutschland’: Early. White flowers to 1 1/2 ft. tall. Bright green leaves.
‘Fanal’: Early. Bronzy foliage is topped by blood-red flowers 1 1/2–2 1/2 ft. tall.
‘Rheinland’: Early. Deep pink flowers 2–2 1/2 ft. tall.
This dwarf grows to 4–8 in. high, with two-toned flowers of white and blue, rose, or pink.
Native to much of the northern hemisphere. Flat, basal rosette spreads vigorously by underground runne...
This strain grows to 20 in. tall and wide, with variegated foliage and blue, red, pink, purple, or whi...