Astilbe x arendsii Amethyst - Astilbe d'Arends, Voile de la mariée, Fausse Spirée

The Astilbe ‘Amethyst’ (× arendsii) is a variety of Arends' astilbe that stands out for its early flowering and unusual amethyst colour. Its long mauve plumes are also softer and airier than those of many cultivars. They rise above dark, fern-like cut foliage and brighten up cool, shady spots in the garden. It is a hardy, robust perennial, well suited to moist soil and banks.

This herbaceous perennial belongs to the Saxifragaceae family. It is a plant whose above-ground vegetation disappears entirely in winter and then regrows from its rhizomatous stump in spring: its foliage is deciduous, but the plant lives for many years. 'Amethyst' was obtained in Germany by nurseryman Georg Arends and introduced in 1920. It belongs to the Arendsii group, a set of complex hybrids derived notably from Astilbe chinensis, A. japonica, A. thunbergii and A. astilboides, which explains the diversity of size, habit and flowering period within the group. These species occur naturally in moist meadows, open woodlands and cool areas of East Asia. 'Amethyst' is characterised by its lofty mauve flowering, distinctly clear of the foliage. The plant forms a rounded clump that spreads slowly. Its growth is moderately fast, reaching mature size in two to five years and measuring 80 to 90 cm in flower with a spread of 45 to 60 cm. The basal foliage forms a mound 30 to 50 cm high. The leaves, a dull dark green, are two or three times divided into oval to lanceolate leaflets, strongly dentate. The petioles and flower stems are a dark red. Flowering occurs from June to July, or even early August in cool regions. The erect flower stalks bear very long loose panicles that gather a multitude of tiny flowers. Their hue ranges between purplish pink and lilac mauve, a colour that is particularly luminous in partial shade. The plumes, which turn beige-brown tones when dry, remain visible in autumn and early winter. The stump withstands harsh winters, down to -20°C at least. The name of this cultivar evokes amethyst, a violet-coloured semiprecious stone. Georg Arends introduced several astilbes onto the market in 1920 named after minerals or gems, among them ‘Bergkristall’, ‘Diamant’, ‘Granat’ and ‘Rubin’.

In a woodland border, this astilbe should be planted in groups of three or five, among broader foliage that will highlight the delicacy of its mauve plumes. You can pair it with other cool-shade perennials such as the hosta ‘Guardian Angel’, blue-green broadly highlighted with cream, the Athyrium filix-femina ‘Frizelliae’ which displays narrow, distinctive fronds, and the Brunnera macrophylla Silver Heart® which covers the ground with silver foliage. In the background, the Rodgersia pinnata ‘Bronze Peacock’ will form a beautiful dark bronze mass. Astilbe can also be grown in a large pot to enliven a shaded terrace, provided it receives abundant and regular watering in summer.