How to Grow and Care for Astilbe -- Garden Chronicle

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Astilbe features plumy spikes of brilliant colors in mid to late summer. With its fern-like leaves, astilbe is a good choice for shady borders and under trees in cottage gardens. Astilbes cultivars range in size from 1½ to 6 feet tall.

Astilbe is a perennial member of the Saxifrage family.

Astilbe’s feathery trusses of tiny flowers can be whitish, pink, or red.

Astilbe is easy to grow in either a sunny or partly shady location. It does best in rich soil if supplied with plenty of water. It can be grown in the open border.

Astilbe is propagated by seed or division. From seed, it requires 10 weeks to 4 months to come into flower

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Get to know Astilbe

Plant type: Hardy perennial
Growing Zones and range: Zones 3 to 9; grows best in Zones 4-8.
Hardiness: Hardy to -25°F (-32°C); does not do well in hot weather
Height and width: 12 to 48 inches (30-122cm) tall; 12 to 36 inches (30-91cm) wide.
Foliage: Neat leafy clumps with compound toothed, almost fern-like leaves with upright plumed-flower clusters
Flower form: Plume-like panicles 7 to 18 inches (18-45cm) inches
Flower colors: Rich red, pink, lilac, salmon, cream, and white
Bloom time: Spring to early summer
Uses: Shady borders, near streams or ponds; a place for a dramatic accent.
Common name: Astilbe, false spirea
Botanical name: Astilbe spp.
Family: Saxifragaceae
Origin: Eastern Asia and North America

Where to plant Astilbe

Astilbe grows well in partial shade. Astilbe needs shade in warm southern regions and less shade in northern regions.
Grow astilbe in deep, humus-rich, well-drained soil.
Astilbe prefers a soil pH of 6.5 to 7.

Astilbe uses and companions

Plant Astilbe in groups in formal and informal gardens.
Plant Astilbe for late color in shaded borders and naturalistic settings.
Grow Astilbe along a stream or pond or in a woodland garden.
good companions for Astilbe include Bergenia, Chelone, Clematis, Delphinium, Hosta, Japanese and Siberian Iris, Trollius.

When to plant Astilbe

Set established plants in the garden in spring or fall. Add plenty of aged compost to the planting bed.
Start seed indoors in spring or summer; seeds germinate in 6 to 8 weeks.
Sow seed outdoors in shaded beds in summer.
Transplant seedlings when they are about 4 inches (10cm ) tall.
Set plants outdoors after the danger of frost passes in spring.
Plants usually bloom during their second year.

Planting and spacing Astilbe

Plant astilbe in humus-rich soil.
Start seed indoors in flats or a six-pack with sterile potting soil. Cover the seed with 1/8 inch of fine soil.
Seeds germinate in 6 to 8 weeks at 65°F (18°C).
Thin or transplant seedlings when they are 4 inches (10cm) tall.
Set astilbe plants in the garden 12 to 36 inches (30-91cm) apart.
Potted plants may be set outdoors from spring to fall.

Chinese astilbe, Astilbe chinensis — Chinese astilbe, *Astilbe chinensis*

How to water and feed Astilbe

Keep the soil evenly moist for astilbes. Make sure the soil is well-drained. Leaves will scorch and brown if the soil dries out.
Fertilizer astilbes every four weeks with an all-purpose fertilizer.

Astilbe care

Mulch around plants to conserve soil moisture.
Divide astilbe every 3 to 4 years in spring or fall.
Remove flower stalks when they turn brown after blooming to keep plants from self-sowing.
Astilbe is susceptible to crown rot in wet soil, especially in winter
Protect astilbe in winter by mulching around the crown of the plant with chopped leaves. Remove the mulch in early spring when growth begins.

Astilbe pests and diseases

Japanese beetles and spider mites may attack Astilbe.
Spider mites may be a problem in warm areas; spray with insecticidal soap.
Control root rot with good drainage and air circulation.

Astilbe propagation

Astilbe seed will germinate in 20 to 25 days at 55°-72°F (13°-22°C).
Blooms ripen into rich russet seedheads from which seed can be harvested for planting the next season.
Plants can be divided every couple of years in spring or fall
Divide crowded clumps every 3 to 4 years and replant in enriched soil. Dig deeply being careful not to disturb the roots. Use a sharp knife to cut through woody roots.
Replant divisions immediately.

Astilbe varieties to grow

Astilbe x arendisii. This is a popular species from which many cultivars have come. Plants range from 24 to 48 inches (61-122cm) tall. Panicles of long narrow flowers rise 12 to 20 inches (30-50cm). Cultivars include ‘Avalanche’ (white flowers), ‘Europa’ (pink flowers), ‘Ostrich Plume’ (salmon pink flowers), ‘Peach Blossom’ (light rose).
A chinensis. This species is available in a range of pastel colors.
A. chinensis pumila. Less than 12 inches (30cm) tall; plumes are rounded and less feathery than others.
A. taqueti. Upright species to 48 inches (122cm) tall; ‘Superba’ is a strong pink cultivar.

Astilbe x arendsii — astilbe

Astilbe x arendsii is a long-lived perennial grown for both its foliage and floral beauty. It thrives in the shade. This astilbe produces foot-long feathery plumes of tiny flowers that come in a range of colors, including white, pink, rose, lavender, peach, and red. Flowers bloom for about a month beginning in early summer to midsummer, depending on the cultivar. The leaves are divided into pointed leaflets with toothed edges and are glossy dark green or bronze.

Size: Flowers 2 to 3 feet tall; foliage chumps 1 to 2 feet and twice as wide.
Light: Light to part shade, tolerates sun in cool regions and if constantly moist.
Soil and moistures: Deep, humus-rich, moist, well-drained soil; keep the soil moist to wet during the growing season.
Planting and propagation: Plant bare-root plants or container-grown plants ½ inch deep in spring, spacing 1 ½ to 3 feet apart. Divide every three years in spring or fall.
Special care: Cut off faded flower stalks if desired or leave them for a natural appearance. Feed heavily. Leaves scorch and shrivel if the soil dries.
Pest and diseases: Rots in winter-wet soil, Japanese beetles, and spider mites can be troublesome.
Climate: Zones 4-8, but performs poorly in arid and hot, humid regions.
Cultivars and similar species: Early ‘Bonn’, medium pink, 2 feet tall; ‘Rheinland’, bright pink, 2 ½ feet tall; ‘Europa,’ pale pink, 1 ½ feet tall; ‘Deutschland’, bright white, 1 ½ feet tall. Mid-Season, ‘Amethyst,’ lilac-violet, 2 feet tall; ‘Bridal Veil,’ creamy white, 2 ½ feet tall; ‘Fanal,’ dark crimson, bronze leaf, 2 ½ feet tall; ‘Peach Blossom,’ light pink, 3 feet tall; ‘Cattleya,’ rose-pink, 1 ½ feet tall; ‘Fire,’ salmon-red, 3 feet tall; ‘Glow,’ ruby-red, 1 ½ feet tall.
Garden use: Elegant planted in groups in formal or informal gardens; graceful along stream or pond or in woodland garden.

Astilbe chinensis var. pumila — dwarf Chinese astilbe

Dwarf Chinese astilbe is a fast-spreading ground cover plant that forms a dense stand of bronze-green toothed leaves. Stiff, narrow plumes of densely packed mauve-pink flowers appear in late summer, blooming for more than a month.

Size: Foliage 6 to 8 inches high; flowers stalks to 1 ½ feet tall. Spreads widely by rhizomes.
Light: Light to full shade.
Soil and moisture: Fertile, moist, well-drained soil best, tolerates dry soil in shade.
Planting and propagation: Plant bare root or container plants 1 ½ inch deep in spring, spacing 2 feet apart. Divide in spring or fall when crowded.
Special care: Remove spent flower stalks.
Pest and diseases: Same as A. x arendsii
Climate: Zones 3-8.
Cultivars: Plants labeled ‘Pumila’ may vary in height. ‘Davidii,’ white, 3 to 4 feet tall, ‘Finale,’ pale pink, 1 ½ feet tall.
Garden use: Use as ground cover beneath shrubs and as edging in mixed borders.

Astilbe simplicifolia — star astilbe

Star astilbe, unlike other astilbes, has undivided leaves, although they are deeply lobed. Loose, nodding spires of white or pink flowers cover the compact leafy mounds in mid-to-late summer. The seedheads that follow the flowers decorate the plants through fall.

Size: Flower spires to 1 ½ feet tall.
Light: Light to full shade.
Soil and moisture: Deep, humus-rich, moist well-drained soil; best kept moist during growing season. Tolerates some dryness.
Planting and propagation: Plant bare-root or container plants 1 ½ inch deep in spring spacing 1 foot apart divide every four years in spring.
Special care: Slow to establish. Three years to maturity.
Pest and diseases: Same as A. x. arendsii
Climates: Zones 4-8
Cultivars: ‘Spite’; shell-pink flowers, bronze foliage, 1 ¼ to 1 ½ feet tail; ‘Bronze Elegance,’ rose-pink flowers, bronze foliage, 1 ½ feet tall, ‘William Buchanon,’ creamy white, 9 inches tall, ‘Hennie Graafland,’ delicate pink, 1 ½ feet tall, ‘Aphrodite’, rosy red, 14 inches tall.
Garden use: Lovely for summer color in an informal shade garden combined with wildflowers, hostas, and ferns.

Astilbe taquetii ‘Superba’ — fall astilbe

This dramatic astilbe brings color to the back of the border or informal garden in late summer. Tall spires of mauve-pink blossoms tower above clumps of handsome, deeply cut, dark green foliage.

Size: Flowers to 4 feet tall; clumps spread 2 ½ to 3 feet.
Light: Light to part shade
Soil and moisture: Deep, humus-rich, moist, well-drained soil; keep moist to wet during the growing season.
Planting and propagation: Plant bare-root plants 2 inches deep in spring, spacing 3 feet apart, or plant container plants. Divide every three or four years in spring or fall.
Special care: Does not need staking despite its height.
Pest and diseases: Same as A. X arendsii.
Climate: Zone 4-8
Cultivars: ‘Purple Lance,’ dark rose-purple, 3 to 4 feet tall; ‘Purpurkerze,’ red-purple flowers, purplish stems, and leaves, 3 feet tall.
Garden use: Excellent late color in shaded borders and naturalistic settings.

Astilbe frequently asked questions

Q: What are the best-growing conditions for astilbe?

A: Astilbes do well in full sun but are best with partial shade, especially in the southern parts of the country. Soil should be just moist with plenty of organic matter mixed in.

Q: How do I propagate astilbe?

A: Division. Divide clumps every third year.

Q: What’s a good way to use astilbe in the garden?

A: Larger astilbe varieties work well in a garden border as a specimen, but most varieties should be set out in groups of three or more. Heights vary from 12 to 40 inches

Q: Can I grow astilbe in winter?

A: Yes. You can force astilbe for winter flowering by potting them in the fall, rooting them, and bringing them into greenhouse heat with plenty of water.

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