Astilbe Plant Growing & Care Guide for Gardeners

Article by Dean Ravenscroft, Ph.D. - Updated 15th Nov 2023

In this Gardener's HQ guide, we'll explore cultivating Astilbe plants in your garden, indoor spaces, and other settings.

Garden Spiraea and False Spiraea: Cultivation & Garden Use

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.

Pink Astilbe by Audreyjm529.

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

Astilbe by Gailf548.

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.

Common Questions

How many members does the Astilbe genus have?

The Astilbe genus has about 18 species. These perennials are popular for their attractive, fern-like foliage and feathery plumes of flowers.

Do members of Astilbe make a good garden or landscaping plant?

Yes, Astilbe plants are excellent in the garden, especially in shady, moist areas. Their colorful flower plumes and feathery foliage offer great texture and color.

Which Astilbe species are most frequently grown by gardeners?

Astilbe x arendsii, a hybrid group with many popular cultivars, is commonly grown by gardeners for its variety of colors and robust growth.

Are members of the Astilbe plant genus fragrant?

While Astilbe flowers are not typically known for their scent, some varieties do have a mild, pleasant fragrance.

What is the perfect location to grow Astilbe?

Astilbe prefers shady to semi-shady areas with moist, well-drained soil. They are perfect for woodland gardens or as ground cover in shady areas.

Is Astilbe invasive in the USA, if so in which states?

Astilbe is not considered invasive in the USA. It is typically a well-behaved garden plant.

How do I remove Astilbe plants from my garden?

To remove Astilbe, dig up the entire plant, making sure to remove all roots to prevent it from growing back.

Summary

The Astilbe genus, part of the Saxifragaceae family, includes about 20 species of perennial plants. Native to East Asia and North America, these plants are recognized for their feathery, plume-like flowers and fern-like foliage. The flowers appear in shades of pink, red, white, and purple, offering a delicate yet vibrant display.

Astilbes thrive in partial to full shade and require moist, well-drained soil. They are perfect for a shade garden or woodland setting and are often planted near water features. While these plants can survive in full sun, they need consistently moist soil to prevent them from drying out. For optimal growth, divide the clumps every few years in early spring or fall.

I hope that you enjoyed this guide on Astilbe. You may also enjoy the following Gardener's HQ growing guides: How to grow Saxifrage and Tellima plants.