Flower · Asteraceae
When to sow michaelmas daisies
Sheets of small daisies in autumn, flowering later than almost anything else in the border and feeding the last insects of the year.
Plant out
2 weeks after
Counted from your last spring frost.
First worthwhile crop
Year 1
After planting, not after sowing.
Hardy in USDA zones
4a to 8b
Winter cold sets the limit here, not the calendar.
Those weeks become real dates once you name a place.
Timing, in frost-relative terms
Seed packets rarely give calendar dates, because a date that suits one latitude is wrong at another. They give offsets from the last spring frost instead, and those offsets are what make michaelmas daisies plantable anywhere.
- Plant out 2 weeks after the last frost.
- Expect a first worthwhile crop in year 1 after planting.
- Hardy in USDA zones 4a–8b.
Getting the timing right
Plant out in spring. Pinch the shoots back by a third in early summer to keep a 1.2m plant self-supporting rather than staked. Divide every two or three years, because clumps run outward and die out in the middle.
Frost tolerance
Hardy to -30C. Mildew in a dry summer is the usual complaint, not winter damage; keeping the roots moist prevents most of it.
Classified as very-hardy, with damage expected below -30°C (-22°F)-22°F (-30°C).