Spring onion · Jinzhong, Shanxi, China
When to plant spring onions in Jinzhong
Main outdoor window
24 Mar - 7 Apr
The window this page is built around.
Timed from last spring frost
21 April
In Jinzhong, on your chosen risk.
Ready to pick
18 May - 7 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 Jinzhong
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 for overwintering
29 Jun - 20 Jul
Counting back 89 days from your first frost so the crop matures in time.
Sow direct
24 Mar - 7 Apr
Four weeks before your last frost.
Harvest
18 May - 7 Jun
Spring onions through the year
Against the frost risk in Jinzhong
Why these dates
Sow direct every three weeks from four weeks before the last frost until about ten weeks before the first. An autumn sowing overwinters for a very early spring crop.
Tolerates about -8C. Autumn sowings survive most temperate winters and stand through cold weather without bolting.
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. Spring onions are timed for direct sowing 4 weeks before it, and this page simply resolves those offsets against the frost date computed for Jinzhong.
The median frost-free season here is 180 days, against 55 to 75 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Jinzhong
Other vegetables to time
Growing spring onions in Jinzhong
When should I plant spring onions in Jinzhong?
Aim for 24 Mar - 7 Apr in an average year. If you would rather not gamble on the weather, wait until 1-15 Apr - by then frost has finished in nine years out of ten.
When will spring onions be ready to harvest in Jinzhong?
Expect to start picking around 18 May - 7 Jun, based on 55 to 75 days to maturity from the planting date calculated for this location.
How much frost will spring onions tolerate?
Tolerates about -8C. Autumn sowings survive most temperate winters and stand through cold weather without bolting.