Aster canus — Clump-forming, upright to bushy

Overview

Aster canus 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. Aster canus 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. It is native to North America.

About

Aster canus is a clump-forming perennial in the Asteraceae that flowers from August to October. It forms upright clumps with simple, often narrow leaves that are roughly textured and deciduous. Best grown in full sun on a fertile loam that stays moist but drains well, it dislikes thin, dry soils. The plant tolerates exposed or sheltered sites and carries a UK hardiness rating of H6–H7.

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 canus is a clump-forming perennial in the Asteraceae, native to North America, that provides a late-season display from August to October. Its habit is upright and clump-forming, with simple, often narrow leaves that are noticeably rough in texture and deciduous through the winter months. Plant where it receives full sun and where the soil is a fertile loam rather than a thin, dry substrate. It prefers neutral to slightly alkaline conditions and a moisture regime that is consistently moist but well drained. Sites facing south, east or west suit it best, and it will tolerate both exposed and sheltered locations. In British horticultural terms it is rated H6–H7, corresponding to very hardy to fully hardy; it is also mapped to USDA zones 4–8. In the garden use Aster canus where a late-summer to autumn presence is wanted in sunlit borders or mixed herbaceous beds with reasonably good soil. Its upright, clump-forming habit and narrow, textured foliage combine with the August-to-October flowering period to extend interest into autumn without needing specialist soils.

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 canus size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright to bushy
Foliage: Deciduous; simple, often narrow and roughly textured
Native to: North America

Care notes

Pruning and caring for Aster canus

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 canus?

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 canus?

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

What soil does Aster canus need?

Aster canus 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.