Italian aster 'King George'

Sun

Full sun; flowering and stem strength decline in shade.

Water

Water regularly during the first growing season. Once established, water during prolonged dry spells, particularly while buds are developing; avoid persistently wet soil.

Soil

Well-drained, moderately fertile soil, preferably neutral to alkaline. Tolerates chalk and some summer dryness but struggles in waterlogged winter soil.

Height

1.5-2 ft (0.45-0.6 m)

Spread

1-1.5 ft (0.3-0.45 m)

Flowers

Late summer to early autumn; violet-blue, daisy-like flowers with golden-yellow centres.

Foliage

Green, slightly hairy, oval to lance-shaped leaves on upright stems; dies back in winter.

Growth

Moderate; forms a steadily expanding clump rather than a running colony.

Care needed

Low

• Pollinators
• Drought tolerant
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.2 ft (0.37 m)

3. After 2 years

   1.5 ft (0.45 m)

4. After 3 years

   1.7 ft (0.53 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

the UK

Growth rate

Moderate

• Plant in spring in cold or winter-wet areas, allowing about 1.5 ft (0.45 m) between plants.
• Water at soil level during establishment and prolonged drought; let the surface dry between waterings.
• Apply a light dressing of compost in spring; avoid heavy nitrogen feeding, which encourages floppy growth.
• Keep mulch away from the crown, especially where winters are wet.
• Use a small support early in the season if stems lean in exposed positions.
• Divide congested clumps in spring every three to four years, or when the centre becomes bare.

Pruning. Remove faded flower heads if you want a tidier plant. Cut dead stems to just above ground level in late winter or early spring, before new shoots extend.

Early spring

Cut down old stems and check that the crown has not become buried under wet mulch.

Spring

Plant new specimens or divide established clumps as fresh shoots appear.

Late spring

Apply a light compost dressing and install discreet supports where needed.

Summer

Water during extended dry weather and check young growth for aphids.

Late summer

Remove faded blooms if desired and water drought-stressed plants while they are flowering.

Autumn

Clear fallen diseased foliage; leave healthy stems standing until late winter if preferred.

• Plant in small groups near the front or middle of a sunny border for a late-season band of violet-blue.
• Combine with stonecrop and ornamental grasses for contrasting flower shapes and autumn texture.
• Use in a freely drained gravel garden alongside catmint and yarrow.
• Repeat along a cottage-garden path where its compact clumps can soften the edge without blocking access.

Garden styles it suits: Cottage garden, English country, Dry gravel garden, New perennial (prairie), Pollinator garden and Blues and silvers.

Plant it with: Autumn stonecrop, Catmint, Yarrow, Feather reed grass, Russian sage and Purple coneflower.

Wildlife: Open flower heads provide accessible pollen and nectar for bees, hoverflies and butterflies late in the growing season.

• Powdery mildew: improve spacing and airflow, water drought-stressed plants at soil level, and remove affected fallen leaves.
• Slugs and snails: protect emerging spring shoots with hand-picking or suitable iron-phosphate bait used according to the label.
• Aphids: wash small colonies off young shoots with water and allow ladybirds and other predators to feed.
• Crown rot or winter losses: improve drainage, keep wet mulch off the crown, and move plants out of waterlogged ground.

Not known to be toxic to people, cats, dogs or horses. No particular part is recognised as poisonous, but it is an ornamental plant rather than a food plant.

• New York aster (Symphyotrichum novi-belgii)

  Usually has smoother, narrower leaves and more densely branched sprays of smaller flowers; many cultivars are taller and spread more strongly.

• Alpine aster (Aster alpinus)

  Forms a much lower mound and usually bears single daisies on short stems in late spring or early summer, rather than branched late-season flower stems.

Aster comes from the Greek word for star, referring to the shape of the flower heads.

Propagation. Divide in spring or take basal cuttings from young shoots in spring. Seed-grown plants will not reliably retain the characteristics of 'King George'.

Accepted botanical name

Aster amellus

Native range

Albania, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Rus, Czechoslovakia, East European Russia, France, Germany and Great Britain.

Measured

Average height 35 cm.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.