Astilbe arendsii

Arends' Astilbe

Common names: Splendid Astilbe, Garden Astilbe, Astilbe

At a glance

Light: Partial shade
Pot size: from 10 l
Lifespan: Perennial
Hardiness: Hardy down to −23 °C
Water need: High

Photo: Sten Porse · CC BY-SA 3.0 · Source

This description was machine-translated.

Description

The Splendid Astilbe is the queen of moist partial shade. From June to August its feather‑light flower plumes in white, pink, salmon and deep red hover over finely feathery, often bronze‑colored spreading foliage. It is the ideal companion for ferns and ferns at the edge of trees or pond banks and remains attractive after flowering with its rust‑brown seed heads.

Care instructions

Plant it in humus‑rich, consistently moist soil in partial shade; it does not tolerate drought, otherwise the leaf margins turn brown. Water abundantly during hot weeks and mulch around the root zone to retain moisture. Divide the clump every three to four years in spring, because it tends to push upward out of the ground over time. Leave the seed heads standing as structure over winter.

The care notes were machine-translated from German.

Garden year

SowingMar–Apr

Germination

Soil temperature: from 15 °C, ideally 20 °C
Days to sprout: 14 to 28 days
Light: Needs light to sprout
Sowing depth: Press in, don't cover
How to start: Start indoors, then plant out

Soil & site

Soil pH

4.0pH 5.5–78.0

Soil type

humus-rich, loamy, moist, nutrient-rich

LightPartial shade

Hours of sunat least 2 h a day

HardinessHardy

Water needHigh

Astilbes want evenly moist, humus-rich, loose soil. Loamy components are ideal because they hold water well. It will not tolerate waterlogging, and it dislikes chalky or purely sandy soils. Before planting, generously improve sandy soil with mature compost so that the moisture does not drain away at once.

Feeding

Heavy feeder

Months

Mar, Apr, Jul

In spring, at the start of growth (roughly March to May), work mature compost in shallowly around the clumps and add some horn shavings. This covers the high nutrient demand slowly and evenly. After flowering in summer you can add a thin mulch layer of compost; this keeps the soil moist, which matters for this moisture-loving plant, and feeds it for the following year.

Overwintering

Astilbe is hardy and gets through winter outdoors without protection in the lowlands of Germany, Austria and Switzerland. Leave the dead foliage standing, as it protects the crown, and cut back close to the ground only in spring before new growth. Cover young plants and containers with brushwood or leaves as a precaution; stand the pot in a wind-sheltered spot and wrap it in horticultural fleece.

Propagation

Methods

Division
From seed

The most reliable method is division every 3 to 4 years, ideally in early spring (March) before new shoots appear, or in autumn (November) during dormancy. Dig up the clump completely and divide the rhizome ball with a sharp spade or knife so that each piece has at least 3 strong buds or shoots; a fist-sized piece is the minimum. Replant the pieces straight away in humus-rich, evenly moist soil (astilbes do not like drought), spaced 40 to 60 cm apart (dwarf varieties 20 to 25 cm). Water in well after planting and mulch.

For sowing, collect ripe seed heads in late summer when they turn brownish, and dry them further in a paper bag. Astilbes need light to germinate, so lay the seed only on top of moist substrate and do not cover it. Keep the substrate constantly moist; at about 22 to 25 °C germination begins after two to three weeks. Note: hybrid varieties (A. ×arendsii) do not reliably pass on their variety characteristics through seed. The offspring vary in colour and habit, and seedlings take around three years to flower for the first time. Mainly suitable for raising new plants from wild types, or if variety purity does not matter to you.