Aster sericeus (Western Silver Aster) — Clump-forming, upright to bushy

Overview

Aster sericeus 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 sericeus 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, wildflower gardens and naturalistic plantings. It is native to North America.

About

Aster sericeus is a clump-forming perennial in the Asteraceae with an upright to multi-stemmed habit. Leaves are deciduous, simple and often narrow with a rough texture. It favours full sun on fertile loam kept moist but well drained and flowers in the UK from August to October. Plant in groups for borders, wildflower or naturalistic schemes.

Wikipedia contributors, CC BY-SA 4.0 — Symphyotrichum sericeum

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 sericeus is a perennial native to North America that forms upright, clump-forming tussocks within mixed herbaceous borders and natural plantings. The foliage is deciduous and typically simple and narrow with a rough texture, and the plant produces a late-summer to autumn display in the UK between August and October. Position the Western Silver Aster in full sun on a fertile loam; avoid thin, dry soils where it will underperform. It prefers a neutral to slightly alkaline soil reaction and a soil moisture balance that is moist but well drained. Give it a south, east or west-facing spot; it will tolerate both exposed and sheltered sites. In UK terms its hardiness is H6–H7, meaning very hardy to fully hardy, and it is also suitable for USDA zones 4–8. Use Aster sericeus in mixed borders to provide late-season structure, or include it in wildflower and naturalistic plantings where clump-forming perennials are wanted. Plant with enough space for the clumps to spread so the upright stems remain visible through the August–October flowering period.

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 sericeus size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright to bushy
Foliage: Deciduous; simple, often narrow and roughly textured
Suggested uses: Borders, wildflower gardens, naturalistic plantings
Native to: North America

Care notes

Pruning and caring for Aster sericeus

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 sericeus?

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 sericeus?

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

What soil does Aster sericeus need?

Aster sericeus 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.