Common name: China Aster
As the name suggests the plant originates from China.
In Japan they are extensively used in the floriculture industry for cut flowers.
This hardy annual has branching stems covered with alternate,50-75mm(2"-3") long coarsely toothed ovate leaves and grows upto 800mm (30") high.
Dwarf varieties: grow from 200-400mm (8-15")high.
Intermediates: 400-600mm 15"-24") high and
Tall varieties: 600-800mm (24"-30") high.
Taller varieties may require some protection /support from high winds.
The flowerheads can be either single or double, single varieties are formed of a ring of petals surrounding a central yellow disc, and the colour range is extensive!
Plants are best situated in an open sunny position,where the soil is well-drained and enriched with liberal amounts of compost.
Callistephus can be prone to attacks of powdery mildew.
Do not plant them too close together, and this will allow better passage of air around the plants which may alleviate the potential problem.
Week 13: Sow the seeds under glass maintaining a temperature of 18°-20°C (64°-68°F)
Germination should take around 4-5 days.
Week 15: Prick out the seedlings if large enough to handle into boxes/trays of potting compost.
Week 16: transfer the trays/boxes to a cold frame to harden off.
Week 21: Plant out 200 - 300mm (8"-12") depending upon the variety.
Planting in groups rather than in rows generally shows them off at their best.
Circa Week 27: remove the crown (centre) bud to encourage flowering side shoots.