In recent years, some of the Latin names of these late summer and autumn blooming perennial have changed to the really hard to say name of Symphyotrichum, Galatella, etc. To most gardeners they are still known as Asters, Michaelmas Daisies or New England Daisies and they are still a must for the autumn border. Most garden asters originate from the United States, while other less commonly grown asters come from Europe and Asia.
Above: Aster novi-angliae 'September Ruby', Aster x frikartii 'Monch', Aster 'The Prince'
Shaped like a daisy, the flowers vary greatly in size. In colour tend to be in the blue/lilac, purple or white bracket, but there is also a good choice of pink flowered varieties that vary in tone from pale pink to vivid fuchsia. There are no yellows or true reds varities. Some blooms are as small as a 5 pence piece, others are bigger than a 50 pence piece. The varieties with the smallest flowers, such as Aster lateriflorus types tend to open along the flower stems, whereas the blooms of the larger flowered Asters are borne in clusters at the top of the flower stems.
Asters are leafy plants. All specie and varieties of Aster carry the leaves up the flower stems, which can be green or near black, an attractive feature that makes these plants even more valuable in the garden. The foliage can be tiny, some are glossy, while others are quite furry. Those plants with furry and small leaves are less likely to suffer from mildew, a problem that disfigure, but never kill a plant. The shape of the clump will vary according to the flower stems of Aster novi-angliae types are thick and very upright, while others such as Aster x frikartii, A. pyrenaeus and A. x herveyii will arch gently forming a neat mound, which is covered with blooms during the flowering period. The more upright varieties, while being handsome and perfect for the back of a border, can be rather bare at the bottom of the clump.
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. There is a aster for every situation in a garden. Some are so ground hugging they are perfect for rockeries, others are so tall they fit perfectly a location at the back of a border.
Above: Aster novi-angliae 'Herbstschnee', Aster 'Starlight', Aster pyrenaeus 'Lutetia'
What To Grow With Asters
Tall asters, make perfect partners for other tall late season blooming perennials including Aconitum, grasses and Eupatoriums. These tend to rigid plants, whereas shorter Asters are more likely to form domes. Some domed Asters are so frothy they will break the rigidness of tall grasses such as Molinia or Miscanthus. They will also complement the short, spiky flowers of Persicaria, a group of plants that blooms well into autumn. Some of the most useful Asters are also the shortest. Low-growing and mounding, they blend perfectly with later blooming plants like Sedum and Origanum.
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'
Caring For Asters
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. 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. 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.
New Names For Asters
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