Aster

ASTERS FOR THE UK GARDENER

Article by David Marks
If you're looking to plant one or more asters in your garden you first need to know the come in large variety of sizes and flower types. There are four commonly grown species of asters in the UK; Aster amellus, frikartii, novae-angliae and novi-belgii. All four share these characteristics:

  • The prefer a full sun or partial position
     
  • They should be planted in good draining ground, especially important if they are to overwinter well. Improve clay soils with grit and lots of
    well rotted organic matter.
     
  • They are perennials so come up year after year.
     
  • They are deciduous, loosing all their leaves and stems in winter.

ASTER AMELLUS

This species (often called Italian asters) has been cultivated in Europe for more than 2,000 years. It’s natural habitat is limestone soil which is free draining and it prefers full sun but will grow fine in partial shade if it is only in the morning.


Aster amellus King George

Aster amellus 'King George'

  • Height and spread is about 50cm / 20in, they do not need staking
     
  • It forms a dense bushy plant which smothers weeds well
     
  • The most well known varieties include 'King George' and 'Veilchenkonigin' which has mauve flowers, ‘Rudolph Goethe’ and ‘Violet Queen’ have violet flowers and 'Sonia' has pinkish flowers. All have yellow centres.
     
  • All varieties of Aster amellus make excellent cut flowers which last about a week.
     
  • The flowers appear in August and continue into September / October.
     
  • They prefer an alkaline to neutral soil which is well drained.
     
  • Fully hardy in the UK

ASTER FRIKARTII

particular frikartii variety, Monch, is probably the best known of these asters. Our advice be to choose this variety.


Aster frikartii Monch

Aster frikartii Monch

  • Height is about 75cm / 30in and a spread of 45cm / 18in, this variety sometimes, but not always, does need staking
     
  • It makes an excellent cut flower which will last a week or more
     
  • The flowering period is exceptionally long from July to early October
     
  • They are suited to most soil types as long as drainage is good.
     
  • Fully hardy in the UK
     
  • Click here to buy Aster frikartii Monch online from our recommended suppliers.

ASTER NOVAE-ANGLIAE

Also known as New England asters, these are a far better choice than their look alikes the Michaelmas Daisy. This species is the one with flowers which close at night although the modern varieties tend not to do this.


Aster novae-aangliae Miss K E Mash

Aster novae-angliae

  • Height is about 75cm / 30in and a spread of 60cm / 24in, this variety often needs staking
     
  • They are not good cut flowers
     
  • It forms a dense bushy plant which smothers weeds well
     
  • The most well known varieties of Aster novae-angliae include 'Violetta' with violet purple flowers, 'Purple Dome' (shorter than most at 55cm high), 'Barr's Pink' an old variety with rose pink flowers, 'Harringtons Pink' also pink flowered. Any of these can be bought online at our recommended supplier, Crocus, by clicking here.
     
  • The lower leaves tend die off early leaving slightly unattractive stalks so some foreground planting will mask this.
     
  • Fully hardy in the UK
     
  • Needs a well drained soil
     

ASTER NOVII-BELGII

This is not so much a species of aster rather it’s a mish-mash of hybrids in all sizes and colours. You need to accept that with this group of asters mildew will almost certainly be a problem and spraying will be required on a regular basis. This is one reason they are not suited to the very amateur gardener.
 
 

GROW ASTERS FROM SEED OR PLANTS?

Although aster seeds are sold in the UK they are for annual plants not the perennials discussed above. So initially your only choice is buy these as pot grown plants. 

Having established an aster plant, taking a cutting is simplicity itself. Forget the complication of cuttings, simply look at the base of the plant and select a suitable side shoot. Gently tease it out and either plant in pots or directly in the ground. The best time is in late spring.

Another easy alternative is to dig up an established clump (three years old or more) and use a spade to cut the clump into into four. Replant wherever you want them to grow. This second method should be used anyway when the plants get to be five years old to reduce congestion.


Aster Sun Helene

Aster Sun Helene

ONGOING CARE OF ASTERS

WATERING
Under normal conditions asters do not require watering, in fact too much water opens all of them up to mildew infections. In drought conditions a thorough soaking with water should see them through two weeks of dry and hot weather.

FEEDING
A twice yearly application of a long-lasting fertiliser such asblood, fish and bone will help improve the flower colour although this is not essential. A handful of fertiliser scattered around each plant and gently worked into the surface of the ground will be fine.

REMOVING / DEADHEADING FLOWERS
To get the longest flowering period from your asters, cut off the flower heads when they have died down. This will definitely extend the flowering season and keep the plants looking at their best the flowering season.

WHERE TO SEE ASTERS IN FLOWER

The National Collection of Autumn Flowering Asters is held at:

Picton Garden
Walwyn Road
Colwall
Malvern
Worcestershire WR13 6QE

Opening Times for the National Collection of Asters are:
1st to 31st August, Wednesday to Sunday 11.00 to 5.00
1st September to 18th October, Monday to Sunday 11.00 to 5.00
It is closed at other times of the year.
The best time to visit is around the end of September.
Old Court Nurseries are on the same grounds as the aster collection and you will have a chance to buy many of the plants grown there.

There is a charge for entry at £3.50 per adult although free to children up to 18 years of age. Admission is free to RHS members.
For some peculiar reason though, RHS members in coach trips are charged the normal entrance fee! Work out the reason for that!

Other shrubs in this series include Ceanothus, Choisya , Hebe, Skimmia, Magnolia, Mahonia , Mock Orange , Lilacs , Potentilla and
Rose of Sharon (hibiscus syriacus). Our main shrub index page can be seen by clicking on the link below.

ASTER SUMMARY

Below we list the key strengths and weaknesses of Asters.

 

HARDY 5 star hardiness rating(to
-18°C)
   
CLAY SOIL Needs improvement 
SANDY SOIL  Yes 
   
DRY SOIL Yes
   
SHADE  No, full sun
   
EVERGREEN  No
   
EASY CARE 3.5 easy care rating 
SMALL GARDENS  Yes 
   
POT / CONTAINER No 
   
FLOWERING  4.5 flowering rating
   
FLOWER TIME July to end Sept.