When to plant China Asters in the UK

Callistephus chinensis

China Aster
China Aster · Callistephus chinensis

A half-hardy annual grown for long-lasting late summer colour. Sow under cover in the UK, harden off carefully, then plant out once frost risk has passed in a sheltered, sunny spot with free-draining soil.

60 cm · Full Sun · Moderate Water

Sow indoors March to April, plant out May.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow indoorsNoNoYesYesNoNoNoNoNoNoNoNo
Plant outNoNoNoNoYesNoNoNoNoNoNoNo

UK averages · set your town for dates worked out from your local frost records · how dates are worked out

Growing guide

What to do through the growing season

Dates for your town

Set your town to see planting windows worked out from local frost history, not a generic UK calendar.

  1. 01

    Sow Seeds Indoors

    mid-March to mid-April UK average · set your town for your exact dates

    Sow seeds in trays or modules around mid-March to mid-April in a light seed compost. Cover with a shallow layer of compost and keep at until they germinate. Keep the compost just moist, not wet.

  2. 02

    Prick Out Seedlings

    early April to early May UK average · set your town for your exact dates Dates as each sowing reaches this stage

    When seedlings are large enough to handle, prick them out from early April into small pots. Handle them by the leaves and keep them growing on in bright light so they do not go leggy.

  3. 03

    Harden Off

    mid-April to early May UK average · set your town for your exact dates

    Start hardening off from mid-April and give them around 10 days to adjust. Put plants outside during the day at first, then leave them out for longer so they settle before planting.

  4. 04

    Transplant Outdoors

    mid-May to late May UK average · set your town for your exact dates

    Plant out from mid-May into fertile, well-drained soil once all frost risk has passed. Space plants apart, water in thoroughly straight after planting, and keep them sheltered from strong wind.

  5. 05

    Deadheading & Maintenance

    mid-June to late October UK average · set your town for your exact dates Dates as each sowing reaches this stage

    Start deadheading from mid-June and keep going until late October. Remove fading flowers regularly so the plant does not set seed, which keeps it producing more blooms right through to the autumn frosts. Keep the soil evenly moist in dry spells and pinch out any weak or floppy growth.

Companion plants

Tap a plant to see why it works (or doesn't) with China Aster.

Good companions

Plants to avoid

Why companion planting matters

Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.

Suggested varieties

Popular varieties of China Aster to consider

Matsumoto

A reliable group with large, single flowers on strong stems, good for cutting and borders.

Milady

Compact plants with double flowers, useful in pots and at the front of a border.

Princess

Tall, cutting-type plants with full flowers and good stem length.