Cosmos · Xiamen, Fujian, China
When to sow cosmos in Xiamen
Main outdoor window
1-15 Feb
The window this page is built around.
Timed from last spring frost
25 January
In Xiamen, on your chosen risk.
Ready to pick
12 Apr - 2 May
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 Xiamen
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.
Start indoors
28 Dec - 11 Jan
Four weeks before your last frost, under cover or on a windowsill.
Sow direct
1-15 Feb
One week after your last frost.
Plant out
1-15 Feb
One week after your last frost.
In flower
12 Apr - 2 May
Cosmos through the year
Against the frost risk in Xiamen
Why these dates
Sow direct around the last frost date. Pinch young plants once to produce a bushier, more productive plant.
Frost-tender at both ends, but flowers freely until the first autumn frost stops it outright.
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. Cosmos are timed from 4 weeks before that frost for an indoor start, with planting out 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Xiamen.
Also in Xiamen
Other flowers to time
Growing cosmos in Xiamen
When should I plant cosmos in Xiamen?
Aim for 1-15 Feb in an average year. If you would rather not gamble on the weather, wait until 1-15 Feb - by then frost has finished in nine years out of ten.
When will cosmos be ready to harvest in Xiamen?
Expect to start picking around 12 Apr - 2 May, based on 70 to 90 days to maturity from the planting date calculated for this location.
How much frost will cosmos tolerate?
Frost-tender at both ends, but flowers freely until the first autumn frost stops it outright.