Aster amellus 'Ultramarine' (European Michaelmas Daisy) — Clump-forming, upright to bushy

Overview

Aster amellus 'Ultramarine' 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 0.7 m tall. Aster amellus 'Ultramarine' 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, cut flowers and wildlife gardens. It is native to Eastern Europe, Ukraine, Portugal, Baltic States, Austria, Czechoslovakia, Romania and Luxembourg.

About

Aster amellus 'Ultramarine' is a clump-forming perennial in the Asteraceae that provides a reliable run of late-season daisy-like flowers from August to October. It reaches about 0.7 m and bears simple, often narrow, roughly textured deciduous leaves. Best grown in full sun on a fertile loam that is moist but well drained and neutral to slightly alkaline. Position on a south, east or west-facing site where it can occupy an exposed or sheltered spot.

Wikipedia contributors, CC BY-SA 4.0 — Aster amellus

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 amellus 'Ultramarine' originates from parts of Europe, including eastern and central regions such as Ukraine, the Baltic states, Austria, Portugal, Romania, Luxembourg and former Czechoslovakia. As a member of the Asteraceae it forms neat clumps of stems that carry late-summer into autumn blooms (August to October), extending the flowering season when many other perennials have finished. Plant it in full sun on fertile loam; avoid thin, dry soils where it will struggle. The species prefers neutral to slightly alkaline soil and a moisture regime that is consistently moist but well drained. It is winter-hardy to UK H6–H7 (very hardy to fully hardy), so it tolerates exposed sites as well as more sheltered positions. Allow room for plants to form 0.7 m tall clumps when establishing new drifts or groups. In the garden, Aster amellus 'Ultramarine' suits mixed borders and informal shrub edges, and the stems are useful as cut flowers. It also fits into wildlife-friendly schemes where late-season blooms are needed. Flowering from August to October provides fresh heads for cutting or to extend colour in borders into autumn.

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 amellus 'Ultramarine' size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright to bushy
Foliage: Deciduous; simple, often narrow and roughly textured
Height: 0.7 m
Suggested uses: Borders, cut flowers, wildlife gardens
Native to: Eastern Europe, Ukraine, Portugal, Baltic States, Austria, Czechoslovakia, Romania, Luxembourg

Care notes

Pruning and caring for Aster amellus 'Ultramarine'

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 amellus 'Ultramarine'?

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 amellus 'Ultramarine'?

Aster amellus 'Ultramarine' prefers full sun. It suits exposed or sheltered positions.

What soil does Aster amellus 'Ultramarine' need?

Aster amellus 'Ultramarine' 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.