(Also known as Michaelmas Daisies, New England Daisies, Symphyotrichum, Galatella)
Above: Aster novi-angliae 'September Ruby', Aster x frikartii 'Monch', Aster 'The Prince'
Asters are a must for the autumn border. Shaped like a daisy, the flowers can be as small as a 5 pence piece or bigger than a 50 pence piece. The colours tend to be in the blue/lilac or purple bracket, with a good choice of pink tones and white, but there are no yellows or true reds. However, it is the shape of the clump that varies most. Ranging from gentle domes to stiffly upright clumps, some are no more than 23cm high, while others grow to over 150 cm. The leaves also vary. Some Asters have soft fresh green leaves, others the are very deep, near-black and shiny.
Where they come from
Most garden asters originate from the United States and are now listed under the really-hard-to-say name of Symphyotrichum. Other less commonly grown asters come from Europe and Asia.
Where to grow Asters
Asters like a well-drained soil that is not too acid, and they don’t mind a clay soil as long as it does not remain wet for any length of time. In my experience most are happy growing in a bit of light shade for part of the day, but generally they do like as much sun as possible.
Above: Aster novi-angliae 'Herbstschnee', Aster 'Starlight', Aster pyrenaeus 'Lutetia'
How to care for Asters
Staking: Asters rarely need staking, although if grown in a very windy spot some taller Michaelmas daisies might topple over. In this situation it may be better to grow stiffly upright New England Asters, or plump for shorter varieties.
Dividing: As most Asters grow rapidly they need dividing every 3 to 4 years to maintain vigour. This includes the popular Michaelmas daisies and New England Asters. Amellus and x Frikartii types take longer to establish and can be left for longer before division.
Diseases: Michaelmas daisies (Aster novi-belgii types) may suffer from mildew. This happens in warm, damp conditions - which is most of the UK - and can be restricted by not crowding the plant.
They look good with
Above: Aster x frikartii 'Monch' & Sedum 'Red Cauli', Aster novi angliae 'Mrs S. T. Wright' with Persicaria amplexicaulis 'Blackfield', Aster 'Wood's Pink with Origanum 'Herranhausen'
Sadly, in 2015 Asters suffered at the hands of botanists. Almost all types of asters from the United States were lumped under one or two new names, while many others from around the world stayed as aster. I don’t object to this, but what I do think is ridiculous is the awful, unpronounceable name they have re-Christened these wonderful Michaelmas Daisies and New England Asters.
Here are some examples of commonly available Asters and their new names:
Aster acris is now Galatella sedifolia
Aster cordifolius is now Symphyotrichum cordifolius
Aster ericoides (as in ‘Pink Cloud’) is now Symphyotrichum ericoides
Aster herveyi is now Eurybia x herveyi (not so long ago this was Aster macrophyllus ‘Twilight’ and a name that still crops up on nursery lists.
Aster laterifolius (as in ‘Horizontalis’) is now Symphyotrichum laterifolius
Aster novae-angliae (New England Aster) is now Symphyotrichum novae-angliae
Aster novi-belgii (Michaelmas daisy) is now Symphyotrichum novi-belgii