Aster macrophyllus (Bigleaf Aster) — Clump-forming, upright to bushy

Overview

Aster macrophyllus is a clump-forming, upright to bushy perennial in the genus Aster, part of the Asteraceae family, with deciduous; simple, often narrow and roughly textured foliage. It typically grows around 0.6 m tall. Aster macrophyllus grows best in full sun, and tolerates fertile loam; avoid thin and dry soils soils and neutral to slightly alkaline pH. Its UK hardiness is rated H6–H7. Suggested uses include borders, woodland gardens and naturalized areas. It is native to Eastern Canada and Northeastern U.S.A..

About

Aster macrophyllus is a clump-forming perennial in the Asteraceae with an upright to well-branched habit and simple, roughly textured leaves. It is deciduous and typically grows to about 0.6 m. Flowering runs from August to October. It prefers fertile, moist loam and should not be placed on thin, dry soils.

Wikipedia contributors, CC BY-SA 4.0 — Eurybia macrophylla

About the genus

Aster is a genus of perennial flowering plants in the family Asteraceae. Its circumscription has been narrowed, and it now encompasses around 170 species, all but one of which are restricted to Eurasia; many species formerly in Aster are now in other genera of the tribe Astereae. Aster amellus is the type species of the genus and the family Asteraceae.

Wikipedia contributors, "Aster (genus)", CC BY-SA 4.0 — Aster (genus)

In the garden

Aster macrophyllus is a clump-forming perennial from eastern Canada and the northeastern United States, carried in the aster family. Plants form upright to well-branched clumps to roughly 0.6 m and die back in winter; flowering takes place from August to October, extending interest into early autumn. Give it full sun on a south, east or west-facing position in fertile loam that holds moisture without becoming waterlogged; avoid thin, dry soils. It favours neutral to slightly alkaline pH and performs in both exposed and sheltered sites. In UK hardiness terms it sits at H6–H7, which equates to very hardy to fully hardy and means it will withstand most winters, including more exposed locations. Use Aster macrophyllus in mixed borders, woodland clearings or naturalised drifts where a late-summer to autumn bloom is wanted at around 0.6 m height. Its season of interest runs late summer into autumn, so plant alongside earlier summer perennials to bridge into the autumn colour phase.

Growing conditions

Best soil and position for Aster

Sunlight: Full sun
Soil type: Fertile loam; avoid thin, dry soils
Soil pH: Neutral to slightly alkaline
Soil moisture: Moist but well drained
Aspect: South, east or west facing
Exposure: Exposed or sheltered
UK hardiness: H6–H7

Plant details

Aster macrophyllus size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright to bushy
Foliage: Deciduous; simple, often narrow and roughly textured
Height: 0.6 m
Suggested uses: Borders, woodland gardens, naturalized areas
Native to: Eastern Canada, Northeastern U.S.A.

Care notes

Pruning and caring for Aster macrophyllus

Cultivation: Plant in an open, airy position — crowding is what brings on mildew. Divide every second or third year to maintain vigour, and pinch or Chelsea-chop the taller kinds in late spring to reduce the need for staking.
Pruning: Deadhead to prolong the display, then cut stems to the base after flowering, or leave them standing through winter for structure and wildlife.
Propagation: Divide in spring, replanting only the vigorous outer growth. Basal cuttings taken in spring root readily.
Pest resistance: Slugs may take young shoots in spring; otherwise generally trouble-free.
Disease resistance: Powdery mildew is the main weakness, especially among the older novi-belgii cultivars. The frikartii hybrids and the aster relatives are markedly more resistant.

Frequently asked questions

How do I grow Aster macrophyllus?

Plant in an open, airy position — crowding is what brings on mildew. Divide every second or third year to maintain vigour, and pinch or Chelsea-chop the taller kinds in late spring to reduce the need for staking.

Where is the best place to plant Aster macrophyllus?

Aster macrophyllus prefers full sun. It suits exposed or sheltered positions.

What soil does Aster macrophyllus need?

Aster macrophyllus grows best in fertile loam; avoid thin and dry soils soil. It prefers neutral to slightly alkaline soil. Aim for soil that stays moist but well drained.