Celery · Changzheng, Shanghai, China
When to plant celery in Changzheng
Main outdoor window
16 Mar - 6 Apr
The window this page is built around.
Timed from last spring frost
2 March
In Changzheng, on your chosen risk.
Ready to pick
4-24 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 Changzheng
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
21 Dec - 12 Jan
Ten weeks before your last frost, under cover or on a windowsill.
Plant out
16 Mar - 6 Apr
Two weeks after your last frost.
Harvest
4-24 Jun
Celery through the year
Against the frost risk in Changzheng
Why these dates
Start ten weeks before last frost but plant out two weeks after it. Celery exposed to a fortnight below 10C after transplanting will bolt rather than form heads.
Light frost is tolerated at maturity, but cold early in life triggers bolting. This crop is unusual in that too-early planting causes failure without any visible frost 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. Celery are timed from 10 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Changzheng.
The median frost-free season here is 287 days, against 80 to 100 days to maturity for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Changzheng
Other vegetables to time
Growing celery in Changzheng
When should I plant celery in Changzheng?
Aim for 16 Mar - 6 Apr in an average year. If you would rather not gamble on the weather, wait until 28 Mar - 18 Apr - by then frost has finished in nine years out of ten.
When will celery be ready to harvest in Changzheng?
Expect to start picking around 4-24 Jun, based on 80 to 100 days to maturity from the planting date calculated for this location.
How much frost will celery tolerate?
Light frost is tolerated at maturity, but cold early in life triggers bolting. This crop is unusual in that too-early planting causes failure without any visible frost damage.