Producing clouds of colourful daisies during the autumn months, whilst the majority of the garden is browning into hibernation, asters are stalwart perennials. The most dazzling of the vast range available are the lilac and blue forms, which glow incredible hues beneath the grey skies and sit so well with autumn’s golden grasses. The soft-pink forms are also beautiful, providing warmth when the weather cools and the perfect foil for falling copper leaves.
Within the 600 or so species and umpteen hybrids of aster, there are also darker shades of pink and purple, as well as white forms, and the plants produce a great range of structure: including upright, bushy, dense, and airy options; some tall and some short. They bloom over a long period, sometimes from August into November, providing hoverflies, bees, and butterflies with vital nectar before winter sets in. Since the peak of this flowering occurs around the feast of Archangel Michael in late September, they are commonly known as Michaelmas daisies. Hence the old rhyme rings, ‘The Michaelmas daisy, among dead weeds, Blooms for St Michael’s valorous deeds. And seems the last of flowers that stood, Till the feast of St Simon and St Jude.’ The latter feast day is held on 28 October, when many asters are still blooming away.
The name ‘aster’ is the Ancient Greek word for star and given because the radiate petals of the flowers give them a starry look. In mythology, they grew when Asteria, the Greek goddess of the stars and the mother of Hecate, wept tears of stars from the night sky. In the old world, the plants were ceremonially burnt at the end of autumn, as the smoke was believed to cast out evil spirits and flush out snakes.
Although several perennials are still commonly known as asters, it is no longer the correct horticultural Latin classification for many of them. A swig of espresso is required before trying to get to grips with the name changes. A few years ago, Aster novi-belgii (the true Michaelmas daisy) became the ridiculous mouthful Symphyotrichum novi-belgii; likewise, A. novae-angliae (the New England aster) and A. ericoides (the heath aster) are now Symphyotrichum. Continuing the tongue-twisting, A. acris was re-named Galatella sedifolia, and A. macrophyllus ‘Twilight’ morphed into Eurybia x herveyi. But others (such as A. x frikartii) remain Aster. Many nurseries ignore the name changes and still refer to them all as asters to prevent frightening customers.
The vast majority are native to North America or Eurasia. A few are British wildflowers (including the sea aster, Tripolium pannonicum), but the key species were introduced here in the early 18th century and became beloved plants in Victorian and Edwardian gardens. In the early 20th century, naturalistic gardener William Robinson used asters ‘as graceful wreaths’ to billow ‘in the October winds . . . making natural and picturesque effects’, and garden designer Gertrude Jekyll planted a whole border of asters at her home, Munstead Wood.
They eventually fell out of favour – probably due to the susceptibility some have to mildew and the invasive vigour of others. But, in recent years, asters have enjoyed a revival via the trend for prairie-style planting. Since many hail from the US prairies and because there are now so many garden-worthy forms that behave themselves, asters have become primary plants in contemporary meadow-style plantings. They pair well with grasses and offer a lovely informal charm, and when they blaze lavender-blue on overcast autumn days, they are hard to beat.
Which asters to grow
The flowers of Michaelmas daises range in size, from the wonderful violet-blue blooms of Aster x frikartii ‘Mönch’, which can reach 5 centimetres, down to the tiny white and pink stars of Symphyotrichum lateriflorum var. horizontale that are held on horizontal stems, producing a pleasing bushy effect. In general, the bigger-bloomed varieties (such as A. amellus ‘King George’) create a traditional look, which works well in cottage gardens; while the small-flowered forms (for example, S. cordifolium ‘Chieftain’) produce a more contemporary mood.
