How to Grow Astilbe Plants in your Garden

Gardener's HQ Guide to Growing Garden Spiraea and False spiraea

Garden plants from the Astilbe plant genus tend to be hardy perennial in nature.

Some of the names in which they are commonly known by include Garden spiraea, Plume flower, False spiraea, and False goatsbeard.

They normally flower from late spring through to early summer.

Description of Garden Spiraea

Astilbe range in height from about 15 cm to 120 cm (6 to 48 inches).

They have appealing plume like flowers that are naturally white or pink; the breeding of the False and Garden spiraea species has extended these colours to be more intense and include pinks and coral colours.

They make great plants for the border when grown in mass and make great plants for a woodland simulation.

Astilbe - plume flower

Pink Astilbe
Pink Astilbe by Audreyjm529.

Astilbe
Astilbe by Gailf548.

Astilbe Growing and Care Guide

Common Names: False Spirea, False Goatsbeard, Spiraea: Garden; Japanese; Star; Chinese; dwarf.
Life Cycle: Hardy Perennial.
Height: 6 to 48 inches (15 to 120 cm).
Native: Asia, North America.
Growing Region: Zones 4 to 9.
Flowers: Late Spring and Early Summer.
Flower Details: Pink, white. Feathery/Plume-like.
Foliage: Herbaceous, Deep cut, Fern like.
Sow Outdoors: Surface. Early spring before last frost or autumn. Spacing: Small species 12 inches (30cm); Large species 20 to 30 inches (50 to 75 cm).
Sow Indoors: Use vermiculite. Water from below. Supply diffused light. Germination time: 20 to 60 days. Temperature 65°F ( 18°C). Start 7 or 8 weeks before expected last frost. Transplant outdoors following the last frost.
Requirements: Shade. Soil pH 5.5 to 7. Humus rich moist soils. Supply a feed in the summer. Regular watering during dry spells. Cutback after flowering in hot areas. Divide every three years in the autumn (in hot areas) or spring (in cool areas).

How to Grow Astilbe

When planting Astilbe outdoors it is best to sow out the seeds on the surface in the early spring, when it is still possible that a frost may occur.

If you plan to grow spiraea indoors first, then the germination period takes from one to two months at a temperature of about 18 degrees.

It is very important to water Astilbe plants from below, as they are hypersensitive to water damage.

Astilbe seedlings should be planted out after the last frost of spring at a spacing of about 30 cm (12 inches) for small varieties, or at 50 to 80 cm (20 to 32 inches) for larger plant tyoes.

Ideally, Astilbe should be planted in moist well drained soil with a pH of 5.5 to 7; ideally in a shaded area.

Caring for Astilbe

Astilbe Care: species such as Garden spiraea, False spiraea, and Plume flower are easy plants to look after - they should be fertilized in the summer and watered during prolonged dry spells.

As a hardy perennial it is best to divide Astilbe plants every three years or so to maintain vigorous growth.