Lesson 1
Choosing varieties
'Aster' now spans Symphyotrichum (Michaelmas daisies, formerly Aster novi-belgii and novae-angliae), Aster amellus (Italian asters), Eurybia (wood asters) and the annual China asters (Callistephus). Pick by season and shape.
Reliable choices: S. 'Little Carlow' (sky-blue, mildew-resistant, the all-rounder); A. × frikartii 'Mönch' (lavender-blue, flowers July–October, RHS AGM); Callistephus 'Matsumoto' mix (annual, brilliant for cutting); S. 'Calliope' (chest-high, deep purple); A. amellus 'Veilchenkönigin' (compact, violet).
Aster groups and what they do
- Symphyotrichum (Michaelmas daisy) — September–October, perennial, can mildew if dry.
- Aster × frikartii — July–October, the longest-flowering aster.
- Aster amellus (Italian aster) — drought-tolerant, mildew-free, compact.
- Eurybia divaricata (wood aster) — for dappled shade, late and willowy.
- Callistephus (China aster) — annual, sown from seed, the florist's aster.
- S. ericoides — heather-like clouds of tiny flowers, brilliant pollinator.