Winter squash · Changzheng, Shanghai, China
When to plant winter squashes in Changzheng
Main outdoor window
16-30 Mar
The window this page is built around.
Timed from last spring frost
2 March
In Changzheng, on your chosen risk.
Ready to pick
4 Jun - 4 Jul
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
9-23 Feb
Three weeks before your last frost, under cover or on a windowsill.
Sow direct
16-30 Mar
Two weeks after your last frost.
Plant out
16-30 Mar
Two weeks after your last frost.
Harvest
4 Jun - 4 Jul
Winter squashes through the year
Against the frost risk in Changzheng
Why these dates
Work backwards: sow date plus days to maturity plus two weeks of curing must land before your first autumn frost. That constraint, not the spring date, is what rules this crop out in cold climates.
A light frost that kills the leaves will not ruin ripe fruit, but it stops any further ripening. Unripe squash does not store.
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. Winter squashes are timed from 3 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 110 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Changzheng
Other vegetables to time
Growing winter squashes in Changzheng
When should I plant winter squashes in Changzheng?
Aim for 16-30 Mar in an average year. If you would rather not gamble on the weather, wait until 28 Mar - 11 Apr - by then frost has finished in nine years out of ten.
When will winter squashes be ready to harvest in Changzheng?
Expect to start picking around 4 Jun - 4 Jul, based on 80 to 110 days to maturity from the planting date calculated for this location.
How much frost will winter squashes tolerate?
A light frost that kills the leaves will not ruin ripe fruit, but it stops any further ripening. Unripe squash does not store.