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Astilbe

Sarah Stehr Sarah Stehr

There are only a few shrubs that flower as magnificently as astilbe, even in the darkest shade. You can find out how to properly plant and care for this valuable shade-loving shrub here.

Origin

There are only a few that flower as magnificently as the astilbe, even in the darkest shade. This makes the shrub, which originates from the Saxifragaceae family, exceptionally valuable. Around 30 or 35 species belong to the astilbe genus that originates predominantly from east Asia, where it grows in damp locations and bright forests. From a gardening perspective, the Chinese astilbe (Astilbe chinensis) and the Arendsii hybrids (Astilbe x arendsii) bred by German perennial gardener Georg Arends are particularly interesting. The astilbe was used as an ornamental plant as early as the 19th century.

Appearance and Growth

Astilbes provide weeks of color in shady gardens from June to September with their vibrant flower panicles which resemble feathers. The color spectrum ranges from white to creme-yellow and pink, down to dark crimson and purple. The panicles are rigid and upright or overhang like feathers and reach lengths of over 21.65 inches. The shrubs can grow between 3.94 and 39.37 inches, depending on the species. Astilbe glaberrima var. saxatilis is an example of an astilbe that remains very small; the largest include the Thunbergii hybrids ‘Professor van der Wielen’, as well as some Chinese astilbe varieties. The inflorescences can be readily worked into dry bouquets. If they are left on the plants, they develop into beautiful infructescences that decorate the winter garden. The shrubs grow bronze or reddish colored shoots in the spring. The heavily separated foliage only turns a rich green color in the summer when it is fully unfurled.

Astilbe

‘Amethyst’ is a rich-flowering hybrid variety (Astilbe x arendsii)

Location and Soil

The shrubs thrive best in fresh, nutrient and humus-rich soil in semi-shady garden areas or on the edges of ponds. The rule applies here: The sunnier the location, the damper the soil should be - only a few species also do well in sunny, dry locations. The shrubs should only be planted in plant containers if a steady water supply can be ensured.

Planting and Care

Astilbes should be regularly fertilized in the spring with compost. This not only supplies the plants with the necessary nutrients, the compost also ensures that the soil remains damp. These shrubs do not require pruning during the season, the dead flower stems alone should be removed by the spring at the latest.

Astilbes can be divided during their rest period - between November and May - should the horsts or carpet become too large. However, the long-lasting shrubs do not require regular division for rejuvenation.

Where to plant

Smaller species such as the dwarf astilbe (Astilbe chinensis var. pumilla) are extremely suitable for planting larger areas under trees and bushes and form a thick carpet here over time with off-shoots. Taller species are best combined with other shade-tolerant shrubs such as hostas, (Anemone hupehensis or A. japonica), Rose of Sharon (Althea), and (Epimedium). Bell flowers (Campanula) and geraniums also work well with astilbes in sunny locations. White flowering astilbes are ideal for brightening dark, shady areas.

Varieties

If you take a look around at the astilbe range of perennial gardeners you will notice that there are predominantly hybrids available here. The breeding efforts of the German perennial gardener Georg Arends produced a lot of varieties in particular. These so-called Arendsii hybrids are highly recommended and many of them were awarded the rating ‘very good’ in the German ‘Staudensichtung’. The variety ‘Glut’ immediately draws the eye in semi-shady garden areas with its vibrant red flower panicles that appear from August to September. It grows to around 31.5 inches tall. The purple-lilac colored ‘Amethyst’ presents its slender flower panicles a little earlier - in July and August. It even grows a little taller than ‘Glut’ to 39.37 inches tall. An equally highly recommended Arendsii hybrid is ‘bridal veil’; the fine, white flowers of this plant appear in July and August. A more recent breed from Japan is the ‘Chocolate Shogun’, one of the few astilbe with dark chestnut-brown foliage that creates a pretty contrast to the creme-white flowers. The variety ‘Red Sentinel’ (Astilbe japonica hybrids) on the other hand has been available in trade shops since the end of the 1940s. Its dark ruby red blossoms become lighter and lighter over time, creating a pretty color show.

Astilbe ‘bridal veil’

‘Bridal veil’ is one of the best white astilbe varieties

Propagation

Most astilbes are through division. The dwarf astilbe can also be propagated through root cuttings. Pure species and open-pollinating varieties can also be propagated through seeds.

Diseases and Pests

Astilbes are occasionally infested by aphids, aphelenchoides, plant bugs, lesion nematodes, or the dreaded black vine weevils. Mildew is a common occurrence when the soil is too dry. Brown leaf margins are not generally an indication of disease, rather of drought damage.

Frequently Asked Questions

What is an astilbe?

Astilbes are from the Saxifragaceae family. Most species originate from the bright forests of east Asia. They are largely characterized by their prolific flowering: They spread joy with opulent, vibrant flowers, even in the darkest shade.

How tall do astilbes grow?

Astilbes grow between 3.94 and 39.37 inches tall, depending on the species. The flower panicles alone grow over 21.65 inches tall.

When can astilbes be planted?

Shrubs such as astilbes are best planted in the fall. This gives them time to grow in well before the winter.

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