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Astilbe: How to Plant, Grow, and Care for Astilbe Flowers | The Old Farmer's Almanac

Astilbe

Caption

Astilbe plant with pink feathery plumes of flowers growing in the garden

Photo Credit
J. Kumpinovica/Shutterstock
Botanical Name
Astilbe
Plant Type
Sun Exposure
Bloom Time
Flower Color
Hardiness Zone
Special Features
Subhead

How to Plant, Grow, and Care for Astilbe

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Astilbes are small flowering plants with feathery plumes in pink or white atop fern-like foliage. They add vibrant color to a shady garden, plus they’re deer-resistant! Planted in the fall or spring, these perennials will flower from late spring into late summer. Learn how to grow and care for astilbe.

About Astilbe

Deceptively delicate in appearance, this moisture- and semi-shade-loving perennial is hardy to Zone 4. Astilbe will provide blooms from late spring to late summer, depending on the variety. A few selections are even fall flowering. With proper moisture, the foliage remains attractive throughout its blooming period. They prefer a soil pH of slightly acidic to neutral.

Astilbes (Astilbe spp.) are clump-forming perennials that belong to the saxifrage family and arise from a stout rootstock. The upright stems bear fern-like green foliage and feathery plumes extending above the foliage in shades of pink, red, purple, or white. The flower clusters vary in size from 6 inches to 2 feet, and the plant height ranges from 6 inches to 5 feet, depending on the variety.

They’ll add a splash of color to perennial borders, wet sites, containers, and groundcovers. The plant attracts butterflies and is resistant to rabbits and deer. The showy flowers are excellent for floral cuttings or use in a dried arrangement.

Planting

Where to Plant Astilbe

Astilbes prefer light to moderate shade, but deep shade will result in few and/or poor flowers; full sun will burn the tender foliage. These plants demand moist, damp soil, but also it must drain well and not puddle, which would ensure their failure. Amend the soil with compost or aged manure (especially in clay types) to increase fertility; astilbe is a heavy feeder. Add perlite and coarse sand to improve drainage.

When to Plant Astilbe

  • Astilbe is usually planted as small plants purchased from garden stores in spring or fall.
  • Starting from seed is very difficult for the home gardener; astilbe can be difficult to germinate, and resulting plants tend to be short-lived.
  • Division is recommended to create new plants at home. Divide existing astilbe plants in early spring as soon as you see new growth.

How to Plant Astilbe

Plant purchased plants about 1 to 3 feet apart, depending on the type. Dig the hole and loosen the soil to about 10 to 12 inches deep. Mix in a handful of compost. Set the crown (where roots and plant connect) just below the soil line. Backfill with the soil removed from the hole. Water well after planting.

If setting bare-root plants, dig holes twice as wide as the plants’ roots and 4 to 6 inches deep. Place the plants so the roots are fanned slightly and pointing downwards, with the crown planted 1 to 2 inches below the ground level. Cover the roots with soil and press firmly.

Water well and keep consistently moist (not soaked).

Growing
  • Check that astilbes are moist. If rain does not occur, water deeply and regularly. Do not sprinkle frequently. 
  • Astilbes are heavy feeders. Fertilize twice a year. Apply a balanced organic compound in spring and a high nitrogen fertilizer in fall.  (Learn more about soil amendments here.)
  • Astilbes are a bit slow to establish but then spread quickly, forming broad clumps with crowns that rise about the soil as they grow. Cover the crowns with compost-rich soil—or, lift and replant.
  • Divide overgrown clumps every 3 to 4 years in the spring. Either replant the divisions immediately or put them in pots to be planted out in the early summer.
  • After the bloom period, clip off any spent flower stems. The foliage will hold visual appeal until fall.
  • After the first frost, the leaves may be yellow. Trim them, if desired. Fresh growth will return in spring.
Harvesting

Cut astilbe flowers and leaves for beautiful arrangements. Vase life is 4 to 12 days. Or, astilbe flowers can be dried. 

Note: Removing flower heads (deadheading) will NOT promote continued flowering.

Gardening Products

Pests/Diseases

Astilbe tends to be rabbit- and deer-resistant
Diseases: bacterial leaf spot, fungal leaf spot, powdery mildew, viruses, Fusarium wilt.
Pests: foliar nematodes, root-knot; tarnished plant bug.