Winter squash · Hamhŭng, South Hamgyong, North Korea
When to plant winter squashes in Hamhŭng
Main outdoor window
4-18 May
The window this page is built around.
Timed from last spring frost
20 April
In Hamhŭng, on your chosen risk.
Ready to pick
23 Jul - 22 Aug
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 Hamhŭng
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
30 Mar - 13 Apr
Three weeks before your last frost, under cover or on a windowsill.
Sow direct
4-18 May
Two weeks after your last frost.
Plant out
4-18 May
Two weeks after your last frost.
Harvest
23 Jul - 22 Aug
Winter squashes through the year
Against the frost risk in Hamhŭng
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 Hamhŭng.
The median frost-free season here is 185 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 Hamhŭng
Other vegetables to time
Growing winter squashes in Hamhŭng
When should I plant winter squashes in Hamhŭng?
Aim for 4-18 May in an average year. If you would rather not gamble on the weather, wait until 10-24 May - by then frost has finished in nine years out of ten.
When will winter squashes be ready to harvest in Hamhŭng?
Expect to start picking around 23 Jul - 22 Aug, 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.