Astilbe, also known as "false goat’s beard", is a genus made up of 12 species of densely clump-forming, rhizomatous perennials that originate from moist sites in mountain ravines, woodlands and stream banks across Southeast Asia and North America.
They are grown for the plume-like panicles — 18-35cm long — of tiny red, pink, purple or white flowers that are borne in the summer as well as their dense fern-like foliage.
The first astilbe to arrive in the UK was a white variety, A. japonica, in the late 1800s. A pink variety in the form of A. davidii arrived later from China and since then numerous hybrids have been developed through breeding programmes to develop a range of flower colours and types.
A. chinensis and A. chinensis var. davidii hybrids are either low-growing (15-25cm) or tall varieties (80-130cm) with slender panicles that are 10-20cm long. A. japonica hybrids grow to heights of between 50cm and 100cm and have long and erect branched panicles that are 10-20cm long.
At the beginning of the 20th century, nurseryman Georg Arends from Germany produced many of the forms of astilbe that are still popular today, including the early varieties A. x rosea ‘Queen Alexander’ and A. x rosea ‘Peach Blossom’.
After World War One, Arends continued developing new varieties and in 1933 his best and most popular cultivar was developed, called A. ‘Fanal’ Award of Garden Merit (AGM). This dwarf variety produces dark-crimson flowers over a long flowering season. Another popular cultivar, the dark-red A. Fire, was developed in 1940.
As their native habitat is generally in damp conditions or next to watercourses, these plants are good for damp, shady corners of a garden. They tolerate bog and waterlogged conditions but can also be grown in flower beds as long as they receive lots of water during dry spells.
Astilbe do well if regularly mulched because this prevents the soil from drying out and they prefer a well-fertilised soil. They can be grown in a clay or sandy soil as long as it is not allowed to dry out. The flowers provide bright, vibrant colour in summer and also fade to decorative shades of brown in the autumn, prolonging the plant’s interest in any garden.
Astilbe are good value for money because they are full-hardy, perennial and will come back year after year with brilliant bright flowers, requiring very little maintenance. They need to be trimmed back in spring ready for the new growth and lifted and divided every few years. Pests and diseases are not often a problem for astilbe, although powdery mildew and leaf spot may sometimes take hold. They do best if the crowns are planted quite shallowly rather than buried underground. Good companion plants are hostas, ferns and grasses.
What the specialists say
David Howard, owner, Howard Nurseries, Norfolk
"The pink-flowered ‘Bressingham Beauty’ is a very popular one and a good white one is ‘Deutschland’, which is a very popular old astilbe. ‘Etna’ is a salmon-red — reds are always popular — and ‘Red Sentinel’ is another good red one. ‘Federsee’ is the best salmon-pink.
"There’s a good range of colours that are bright and attractive, but they must have a good he southern side of the country is that it might be too dry for them in certain areas, bsupply of water to keep them going — no doubt about it. They do well with garden centres. Landscapers do use them but not as much as they ought to."
Billy Carruthers, owner, Binny Plants, West Lothian
"My favourites are ‘Hennie Graafland’, which is one of the little ones — a wee beauty. The foliage even before it flowers and after it finishes flowering makes it a wonderful plant. ‘White Gloria’ is another beauty and the best red one is ‘Montgomery’, which has dark foliage and really good red flowers.
"For us here in Scotland they are really tough plants. They grow in a whole range of conditions, though they don’t like it too dry. They have great foliage even when they’re not in flower and we tend to find they look good as grasses as well.
"They don’t really have any problems — they’re not affected by anything. They’re not eaten by slugs or rabbits and they are pretty much trouble-free plants. The only downside for tut they are almost the perfect garden plants and can take any amount of rain. That’s why I grow so many of them — about 30."
Malcolm Pharoah, Marwood Hill Gardens, Devon
"We grow a wide range of them here as we have the National Collection. Growing them in containers works well for them so they make plants that can be sold in nurseries and garden centres. Although astilbe like moist soil, and this is a drawback in drier counties of the South East, they can be grown in shadier sites and will flower just as well. Obviously in shady sites they won’t need as much water as in full sun.
"They like to be lifted and divided quite regularly, say every five or six years. Obviously, this means that you get extra plants but by dividing them and even replanting small bits they get more vigorous. If you don’t divide them, they loose vigour and become smaller.
"We find the dwarf japonica types that flower in late June and early July sell the best, particularly the deep-reds such as ‘Etna’. ‘Fanal’ is also very good. A good white is ‘Deutschland’ or ‘Bridal Veil’. Other good sellers include ‘Erica Glow’ or ‘Fire’. Some of the newer novelties from Holland are very good, including ‘Diamonds and Pearls’ and ‘Delft Lace.’ These have good foliage — either golden or bronzy. This seems to be the new development in astilbe breeding."
Steve Guy, planteria manager, Squire’s Twickenham Garden Centre
"We used ‘Delft Lace’ in our Squire’s RHS Hampton Court Palace Flower Show garden by the pond and it’s a new variety and one of the best. It has slightly crinkled foliage and starts dark then comes out pinker.
"Astilbe still sell quite well — they’re a popular plant. They like a bit of moisture and will take the sun as long as they get moisture. The lovely busy foliage you get in the spring is a bonus because people just think about the bloom.
"A. chinensis var. pumila grows to 6-9in and larger ones grow to 3-4ft. The best are ‘Delft Lace’, ‘Fanal’ and ‘Koln’. There’s a new series called ‘Visions’ that have nice soft lilacs and pinks.
Pumila is quite nice almost as ground cover. ‘Ostrich Plume’ is a white one and ‘Inshriach Pink’ is almost a peachy pink. When I was a kid I had a thing about astilbe and really enjoyed them. They didn’t have so many varieties then. It was a childhood obsession."
Species and varieties
A. x arendsii are 50-120cm tall with panicles up to 45cm long in the largest cultivars. Varieties in this cultivar group include:
A. ‘Brautschleier’ AGM (H7) (syn. A. ‘Bridal Veil’) produces elegant sprays of nodding white flowers that open in midsummer from bright-green buds and then fade to a creamy yellow. Height and spread: 75cm.
A. ‘Bressingham Beauty’ has spreading, bronze-flushed, mid-green leaves and bright-pink flowers that are borne in midsummer. Height: 90cm. Spread: 60cm.
A. ‘Fanal’ AGM (H7) has dark-green foliage and dense panicles of long-lasting dense crimson flowers. Height: 60cm. Spread: 45cm.
A. ‘Federsee’ has conical panicles of deep rose-pink flowers and mid-green foliage. Height: 60cm. Spread: 45cm.
A. chinensis bears panicles of pinkish white flowers. Height and spread: 60cm.
A. chinensis ‘Diamonds and Pearls’ has a pure-white flower along with its golden foliage. Height: 70cm.
A. chinensis var. pumila AGM (H5) is a dwarf variety with red/green leaves and dense panicles of reddish/pink flowers. Height: 25cm. Spread: 20cm.
A. chinensis var. davidii features bronze-tinted leaves and slender panicles of purple/pink flowers. Height: 2m. Spread: 60cm.
A. ‘Delft Lace’ has silvery/blue-green leaves and red stems bearing salmon-pink buds that open to form pale-pink flowers. Height: 80cm. Spread: 50cm.
A. x japonica has branched panicles of flowers. Varieties in this cultivar group include:
A. ‘Deutschland’ features erect panicles of pure-white flowers and bright-green foliage. The flowers are borne in late spring. Height: 50cm. Spread: 20cm.
A. ‘Montgomery’ has tapering panicles of deep-red flowers and red/bronze foliage. Height: 70cm. Spread: 45cm.
A. ‘Rheinland’ AGM (H7) has mid-green foliage and upright panicles of rich pink flowers that are
borne throughout the summer. Height: 50cm. Spread: 45cm.
A. simplicifolia AGM (H7) has small arched panicles that reach 10-20cm in length. They are dwarf growing varieties (30-50cm in height), which makes them ideal for the front of borders.
They can tolerate drier soil conditions than many other types. Varieties in this cultivar group
A. ‘Gnom’ with reddish/green leaves and tiny pink flowers in dense spikes. Height and spread: 15-20cm.