Sunflower · Qujing, Yunnan, China
When to sow sunflowers in Qujing
Main outdoor window
5-19 Mar
The window this page is built around.
Timed from last spring frost
26 February
In Qujing, on your chosen risk.
Ready to pick
14 May - 13 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 Qujing
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.
Sow direct
5-19 Mar
One week after your last frost.
In flower
14 May - 13 Jun
Sunflowers through the year
Against the frost risk in Qujing
Why these dates
Sow a short row every two weeks until ten weeks before first frost for continuous cut flowers rather than one brief spectacle.
Seedlings are killed by frost. Once flowering, stems tolerate a light autumn frost without damage.
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. Sunflowers are timed for direct sowing 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Qujing.
The median frost-free season here is 279 days, against 70 to 100 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Growing sunflowers in Qujing
When should I plant sunflowers in Qujing?
Aim for 5-19 Mar in an average year. If you would rather not gamble on the weather, wait until 22 Mar - 5 Apr - by then frost has finished in nine years out of ten.
When will sunflowers be ready to harvest in Qujing?
Expect to start picking around 14 May - 13 Jun, based on 70 to 100 days to maturity from the planting date calculated for this location.
How much frost will sunflowers tolerate?
Seedlings are killed by frost. Once flowering, stems tolerate a light autumn frost without damage.