Heath aster

Heath aster: how do you recognise it?

Habit

Upright, finely branched clump 80–100 cm tall and 50–60 cm wide, with firm, wiry stems.

Leaves

Very narrow and short, 1–3 cm, dark green and slightly rough; reminiscent of heather.

Flower

Small daisy-like flowers about 1 cm across, borne in large numbers at the tips of the branches in September and October.

Colour

White with a yellow centre that turns pink or brown; there are also pale blue and pink cultivars.

Roots

Creeping rhizomes: the plant slowly spreads into a clump and divides easily.

Flowering: September–October · Plants: March–May · Pruning: March and May

Why grow it?

• Flowers in September and October with thousands of fine little stars, an airy cloud in the autumn border.
• An important late nectar source for bees, bumblebees and butterflies.
• Drought tolerant and little troubled by disease: a tough perennial for sunny, well-drained soil.
• Lovely as a cut flower and as a filler in an autumn bouquet.
• The fine, heather-like foliage and slender stems give structure even before flowering.

Heath aster: where does it grow best?

• Full sun for the richest flowering; in shade it becomes tall and floppy.
• Well-drained soil: sand or loam, acid to chalky. It prefers soil that is not too rich.
• Dry to reasonably moist; it tolerates drought better than most autumn asters.
• Space plants 50–60 cm apart, preferably in a group.

Light

Sun

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Dry or normal

Size

0.9 m tall, 0.6 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Ornamental grasses: Plumes and fine grasses beside the little stars make an airy whole.
• Stonecrop: Flowers at the same time, in broad pink heads.
• Purple coneflower: Flowers and seedheads in warm tones next to the white cloud.
• Japanese anemone: Flowers at the same time, in pink and white.
• Lavender: A grey, scented edging in front of the heath aster.

Heath aster: when and how to plant it?

Plant in March–May.

1. Plant between March and May, when the soil is neither frozen nor waterlogged.
2. Dig a hole slightly wider than the root ball and mix in a little compost, or sand if the soil is heavy.
3. Set the plant at the same depth as in its pot and firm the soil well.
4. Leave 50–60 cm between plants.
5. Water thoroughly straight away and water in dry spells during the first year.
6. Spread a thin layer of compost or fine grit around the base; keep the crown clear.

Care

Water

Water in dry spells during the first year. After that it is very drought tolerant; only long dry summers call for a drink.

Feeding

Feed little or not at all: on rich soil it grows too tall and flops. An occasional bit of compost is enough.

Support

On poor soil it stands on its own. On a rich spot, a light support of twigs or a ring helps.

Pinching

Pinch back the shoots by a third at the end of May for a more compact, sturdier plant. Flowering then starts slightly later.

Dividing

Divide the clump every three or four years in spring to keep it vigorous.

Tip: Pinch the shoots back by a third at the end of May: the plant becomes more compact and sturdy enough to stand without support. On poor, dry soil this is not necessary.

Heath aster: when to prune it?

Pruning months: March and May.

When: From late February to March, before the new shoots appear; optionally a light trim at the end of May.

How:

• Cut the old, dead stems down to 10 cm above the ground.
• Leave the spent flower sprays standing over winter: they decorate the garden and give birds and insects food and shelter.
• Pinch back the shoot tips by a third at the end of May for denser growth and less flopping.
• Clear dead leaves from around the base.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April: lift the clump, split it into hand-sized pieces with roots and replant straight away.

Cuttings

In May: take 5–8 cm cuttings from young shoots and root them in moist cutting compost in a bright spot. They root within a few weeks.

Seed

In spring on moist seed compost, lightly covered; the species comes from seed, but cultivars do not always come true.

Heath aster: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy, to about −35 °C: no protection is needed, even in hard Belgian winters.
• Leave the stems standing until spring: with frost on them they decorate the winter garden.
• In a pot: stand it against a sheltered wall and wrap the pot in hessian or bubble wrap so the roots do not freeze.

Diseases and pests

• Flopping: On rich or too shady spots it grows tall and floppy. Pinch in May, do not feed and choose a sunny position.
• Powdery mildew: White powder on the leaves, especially in stuffy summers. Plant with enough space, water at the base in long dry spells and cut off affected stems.
• Slugs: Young shoots are eaten bare in spring. Collect slugs in the evening or set a trap.
• Shoots collapsing: Waterlogged soil makes shoots die off. Ensure good drainage.

Through the year

• March: Cut old stems back to 10 cm. Divide the clump. Plant.
• April: Plant or move. Little feed, a bit of compost.
• May: Plant. Pinch shoots back by a third. Watch for slugs.
• June: Growth. Water in long dry spells.
• August: Buds form. The plant is almost ready to flower.
• September: Flowering begins. Cut for a bouquet.
• October: Full flower, bees and butterflies visit for the nectar.
• November: Nothing to do. Leave the flower sprays for insects and birds.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The species name ericoides means ‘heath-like’, after the fine foliage that resembles heather (Erica).
• In North America the species grows naturally in dry, open places, from prairie to roadsides.
• The sprays are popular with florists as a filler in bouquets.