Red tones to expect
Red summer asters run from crimson to wine, and most are fully double so the petals form a dense dome. The colour looks strong against the green of the plant and works well with white and cream asters in a mixed vase. Because Callistephus chinensis is an annual, you start from seed each year, which lets you pick the exact red you prefer.
From seed to flower
Seeds are sown from August to October in most of temperate Australia. They germinate in about a week or two in a warm spot. Plant out the seedlings 25 to 30 centimetres apart, in full sun, once the frost risk has passed. Flowers open from January and often last through to March or April.
- Pinch the tips when plants are about 15 centimetres tall.
- Support taller varieties with netting or twiggy stakes.
- Feed lightly during active growth.
- Remove spent flowers to prolong the display.
The risk to know about
China asters are prone to fusarium wilt, a soil fungus that makes plants collapse. The best defence is simple: do not plant asters in the same ground twice running, and use clean pots and compost.
Red asters in water
Red asters last about a week to ten days when cut at half-open and kept in cool water. Remove foliage below the waterline, which quickly fouls the water.
Easy on dogs and cats
The ASPCA rates aster as non-toxic for dogs, cats and horses.
