Michaelmas daisy · Karaj, Alborz Province, Iran
When to sow michaelmas daisies in Karaj
Main outdoor window
15 May - 12 Jun
The window this page is built around.
Timed from last spring frost
1 May
In Karaj, on your chosen risk.
Ready to pick
1 Sep - 31 Oct
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Karaj
Each window is a range, not a single day. Earlier in the range buys you a longer season; later in it buys you a safer one.
Plant out
15 May - 12 Jun
Two weeks after your last frost.
In flower
1 Sep - 31 Oct
Michaelmas daisies through the year
Against the frost risk in Karaj
Why these dates
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.
Hardy to -30C. Mildew in a dry summer is the usual complaint, not winter damage; keeping the roots moist prevents most of it.
Seed packets and extension guides express timing as weeks either side of the last spring frost, because that is the only reference point that travels. Michaelmas daisies are timed with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Karaj.
Hardiness is not the obstacle here. Karaj is zone 6b, comfortably inside the range this crop is rated for, so an established plant should come through an average winter without protection.
Do not expect a crop in the first year. A plant set out now should give its first worthwhile pick around year 1, and will then produce every year after that, which is what makes the planting decision worth getting right the first time.
Also in Karaj
Other flowers to time
Growing michaelmas daisies in Karaj
When should I plant michaelmas daisies in Karaj?
Aim for 15 May - 12 Jun in an average year. If you would rather not gamble on the weather, wait until 31 May - 28 Jun - by then frost has finished in nine years out of ten.
When will michaelmas daisies be ready to harvest in Karaj?
Expect to start picking around 1 Sep - 31 Oct, based on 140 to 170 days to maturity from the planting date calculated for this location.
How much frost will michaelmas daisies tolerate?
Hardy to -30C. Mildew in a dry summer is the usual complaint, not winter damage; keeping the roots moist prevents most of it.