Astilbe: profile, propagation & overwintering

Few plants thrive as well in semi-shady locations as astilbe. The delicate flowers of these extraordinary perennials can be admired from July to August.

The magnificent flowering ornamental plant lives up to its name. With their showy flowerheads in a wide range of colours, astilbe is truly a sight for the eyes. Their lush flowers are wonderful in the garden, as hardly any perennial develops such a magnificent show of flowers in mid-summer in semi-shady locations.

Astilbe: origin and characteristics

Originating from East Asia, the astilbe (Astilbe) is a perennial herbaceous perennial that grows in damp areas of sparse woodland. With its magnificent flowers even in semi-shady areas, it is ideal for brightening up less sunny parts of the garden. A humid site is important for astilbe – the sunnier it is, the more moisture the soil must provide. It is best planted together with larger and smaller shade perennials and forms dense clumps through rhizomes. About 30 to 35 species belong to the genus astilbe, of which about 8 species are used in horticulture. Astilbe has feathery, bushy flowerheads consisting of 500 to 2,000 individual flowers. The colour spectrum of the varieties ranges from white, pink and red to yellow and purple. The long panicles are either tightly upright or hanging, as in the case of the Thunbergii hybrids, for example.

How tall does astilbe grow?
Depending on the species and variety, an Astilbe can reach a height of between 20 and 120cm.

When does astilbe flower?

Depending on the species, the flowering period ranges from May to September. With a skilful choice of astilbe varieties and species, you can enjoy the magnificent flowers of these perennials all summer long.

Is astilbe bee-friendly?

No, despite the lush flowers, astilbe is not particularly bee-friendly. Only the Astilbe chinensis attracts bees and is often pollinated by beetles.

Winter hardiness

Generally speaking, astilbe is hardy and can withstand cold and frost outdoors down to about -28°C. However, in locations with very severe winters and with waterlogged soils, it is advisable to cover astilbe with brushwood before the onset of winter to protect them from heavy frost and moisture. Potted plants should definitely be winterised, however, and the planter should preferably be wrapped well with an old blanket, bubble wrap or other insulating material to protect the roots. Alternatively, the plant can overwinter in a cool greenhouse or an unheated conservatory.

Propagation

To propagate the astilbe successfully, there are several methods, which may be more or less suitable depending on the variant of astilbe. Most species are propagated by division, others, such as dwarf astilbe (Astilbe glaberrima), are best propagated by root cuttings. Clumps should be divided in spring so that the plants can develop strong roots over the summer. To divide clumps, proceed as follows:

• Dig up the plant in early spring
• Gently pull the root ball apart with your hands
• Place individual pieces in fresh substrate at a distance of about 40 – 60cm
• Lay a drainage of expanded clay to avoid waterlogging
• Planting astilbe

Is astilbe poisonous?

Astilbe is not poisonous, neither to humans nor to pets such as dogs and cats. Parts of individual varieties can even be eaten. The young leaves of the Astilbe thunbergii hybrids are used for making tea.

These unique plants can accentuate and brighten up semi-shady locations in the garden. They also look particularly good in combination with ornamental grasses.