• Maureen Little

When is a Michaelmas Daisy not an Aster?

Updated: Mar 30, 2020

Q: When is a Michaelmas Daisy not an Aster?

A: When it’s a Symphyotrichum!

Many plants that we used to know as Aster have been reclassified. In fact, some of the new names came into being back in 2015, but us gardeners are sometimes a bit stick-in-the-mud when it comes to change. And not just gardeners – I visited a garden centre recently and found what is now Symphyotrichum still labelled as Aster.

Symphyotricum novi-belgii 'Dandy'

Why the change? Suffice it to say that originally a plant was included in a particular group because of its visible characteristics. With advances in genetic technology, however, it has now been discovered that many plants aren’t what they seem. Apparently, some aren’t as closely related to others as was first thought, and vice versa. Which is what has happened to a number of plants formerly known as Aster.

That’s why our old friends the Michaelmas Daisy, which used to be called Aster novi-belgii or Aster novae-angliae, now find themselves with the monikers Symphyotrichum novi-belgii and Symphyotrichum novae-angliae.

The common name is indicative of the time of year that they flower: Michaelmas is celebrated on 29 September. They are some of the best autumn-flowering perennials, although a few gardeners avoid them because of their susceptibility to mildew. It is true that some older varieties, particularly the S. novi-belgii cultivars, suffer from this affliction, but newer ones appear to be less vulnerable.

Aster x frikartii 'Moench'

One Aster that remains Aster, however, is Aster x frikartii. To my mind one of the best varieties is ‘Mönch’. It has masses of lavender-blue flowers with orange centres held above dark green leaves, and it is pretty well trouble-free. It looks good with just about anything you plant alongside it, too.

I’ll be featuring other plants that are having an identity crisis over the coming weeks.