Zinnia · Huainan, Anhui, China
When to sow zinnias in Huainan
Main outdoor window
23 Mar - 6 Apr
The window this page is built around.
Timed from last spring frost
16 March
In Huainan, on your chosen risk.
Ready to pick
22 May - 11 Jun
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 Huainan
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
16 Feb - 2 Mar
Four weeks before your last frost, under cover or on a windowsill.
Sow direct
23 Mar - 6 Apr
One week after your last frost.
Plant out
23 Mar - 6 Apr
One week after your last frost.
In flower
22 May - 11 Jun
Zinnias through the year
Against the frost risk in Huainan
Why these dates
Direct sowing after last frost usually beats transplanting - zinnias dislike root disturbance and catch up quickly.
Killed by the first frost at either end of the season. Strictly a warm-season flower.
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. Zinnias 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 Huainan.
The median frost-free season here is 252 days, against 60 to 80 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Huainan
Other flowers to time
Growing zinnias in Huainan
When should I plant zinnias in Huainan?
Aim for 23 Mar - 6 Apr in an average year. If you would rather not gamble on the weather, wait until 2-16 Apr - by then frost has finished in nine years out of ten.
When will zinnias be ready to harvest in Huainan?
Expect to start picking around 22 May - 11 Jun, based on 60 to 80 days to maturity from the planting date calculated for this location.
How much frost will zinnias tolerate?
Killed by the first frost at either end of the season. Strictly a warm-season flower.