A large genus of magnificent garden plants. Under this heading we shall deal only with the; asters will be found under the title Callistephus. For clarity they may be divided into two :
Spring-flowering asters (A X alpellus, A. alpinus, A. farreri, A. tongolensis and A. yunnanensis.)
Late-flowering asters (A. amellus, A. cordifolius, A. dumosus hybrids, A. ericoides, A. X frikartii, A. linosyris, A. novae-an gliae, A. novi-belgii and A. sedifolius.)
Mainly border and rock plants, they provide beautiful colour combinations. Autumn-flowering asters are particularly strong. All species require plenty of sun.
Spring-flowering asters need well-drained, calcareous soil, but the other species must definitely not be grown in too damp a situation either.
Asters are easily increased by division.
X alpellus: Height to 15 cm; violet-blue with an orange centre in early and mid summer. Aster alpinus: Height 15-25 cm; blue or blue-violet flowers in early and mid summer. Garden varieties are white, violet, pink etc.
Aster amellus: Height 30-60 cm, flowering season mid summer to early autumn, depending on the variety. ‘Blue King’, deep violet; ‘Heinrich Seibert’, pale pink; ‘Hermann Lons’, lavender coloured; ‘King George’,, and many other strains. Excellent border plant. Aster cordifolius: Height 60-150 cm; flowering season early to mid autumn. The flowers are almost white with a little violet; the centre is yellow.
Aster dumosus hybrids: Height 15-40 cm; flowering season early to mid autumn. ‘Alice Haslam’ is deep rose red; ‘Autumn Joy’, lavender; ‘Lady in Blue’, pure blue; ‘Professor Anton Kippenberg’, lavender; ‘Snow Cushion’, white.
Aster ericoides: Height 60-100 cm; flowering early to late autumn. Flowers pink, white or creamy, small but fine. Aster farreri: Height to 90 cm; deep-violet flowers with an orange centre in late spring and early summer. ‘Berggarten’ is the most beautiful variety.
Aster X frikartii: Height 50-70 cm; flowering season late summer to early autumn. Bright-blue flowers, in ‘Wonder of Staffa’ shading to violet; very fine. Aster linosyris: Height 40-60 cm; small yellow flower-heads in dense plumes in early autumn.
Aster novae-angliae: Height to 250 cm; flowers from early autumn onwards. Theare hairy. Colours are crimson, rose red, blue, violet etc.
Aster novi-belgii: Height 50-150 cm; flowering season from early autumn onwards. Can be distinguished from the previous species by the fact that its stems are not downy, and is the best known late-flowering aster. Among the varieties available are: violet, ‘Eventide* and ‘Harrison’s Blue’; pale violet, ‘Marie Ballard’, ‘October Dawn’ and ‘Plenty’; purple pink, ‘Fellowship’, lassie’ and ‘Tapestry’; dark purple-red, ‘Crimson Brocade’ and ‘Winston Churchill’; purple red, ‘Melbourne Bell’ and ‘Twinkle’; white, ‘White Ladies’.
Aster sedifolius: Height 60-100 cm; flowering season late summer and early autumn. Ray florets are lilac; tubular florets, yellow. The variety most frequently grown is ‘Nanus’ — lilac pink, not exceeding 25 cm. Aster tongolensis syn Aster subcaeruleus: Height 30-60 cm, flowering season late spring and early summer, making it one of the earliest flowering species. ‘Berggarten’ is violet coloured; ‘Napsbury’, heliotrope; ‘Wartburgstern’, deep purple.
Aster yunnanensis: Height 20-30 cm; dark-blue flowers with brown-black centres in late spring to mid summer.