How to grow China aster

Callistephus chinensis · annual aster

Annual from China with daisy-like to fully double, pompom flowers 7–12 cm across in white, pink, red, blue, purple and yellow, from mid-summer into autumn. A classic cut flower; not to be confused with perennial asters.

Quick facts

Type	Flower
Family	Asteraceae
Light	Full sun
Soil pH	6–7.5
Frost	does not tolerate frost
Soil for sowing	from 18 °C
Germination	10 days
Seedlings ready	42 days
Where it grows	Greenhouse, Open ground

When to plant

Sow for seedlings about 7 weeks before planting out.

Plant out in open ground about a week after your last spring frost, once the soil is warm.

In an unheated greenhouse everything moves about three weeks earlier.

Frost dates · When to plant

Care

Greenhouse

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	16…21 °C	—
Growth	every 3 days	—	—
Flowering	every 2 days	—	—

Open ground

Stage	Watering	Temperature	Feeding
Seedlings	every 2 days	16…21 °C	—
Growth	every 3 days	—	—
Flowering	every 2 days	—	—

Growing notes

Light

Best in full sun; tolerates part shade.

Soil

Rich, well-drained soil that stays consistently moist, pH 6–7.5. Grow it in a different spot each year, as wilt and other diseases build up in the soil.

Care

Sow 3 mm deep indoors 6–8 weeks before the last frost at 21–22 °C; seedlings come up in 10–14 days. Move them to small pots once the first true leaves appear, and plant out 15–30 cm apart after the last frost. Keep the soil moist and never let it dry out, and give the plants good air circulation. Tall varieties need staking. Long days in the first weeks speed up flowering. Aster yellows, spread by leafhoppers, makes plants yellow with green, twisted flowers; pull and destroy such plants.

Pests and diseases of China aster

Sources

Figures checked against these sources.