Melon · Acheng, Heilongjiang, China
When to plant melons in Acheng
Main outdoor window
20 May - 3 Jun
The window this page is built around.
Timed from last spring frost
29 April
In Acheng, on your chosen risk.
Ready to pick
29 Jul - 18 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 Acheng
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
1-15 Apr
Four weeks before your last frost, under cover or on a windowsill.
Plant out
20 May - 3 Jun
Three weeks after your last frost.
Harvest
29 Jul - 18 Aug
Melons through the year
Against the frost risk in Acheng
Why these dates
Plant out three weeks after last frost, not two. Black plastic mulch or a cloche raises soil temperature enough to make melons viable several hundred kilometres further north than they otherwise would be.
Melons stop growing below 15C and never fully recover. Frost is fatal, but the real limit is cool nights.
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. Melons are timed from 4 weeks before that frost for an indoor start, with planting out 3 weeks after it, and this page simply resolves those offsets against the frost date computed for Acheng.
The median frost-free season here is 159 days, against 70 to 90 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Acheng
Other vegetables to time
Growing melons in Acheng
When should I plant melons in Acheng?
Aim for 20 May - 3 Jun in an average year. If you would rather not gamble on the weather, wait until 29 May - 12 Jun - by then frost has finished in nine years out of ten.
When will melons be ready to harvest in Acheng?
Expect to start picking around 29 Jul - 18 Aug, based on 70 to 90 days to maturity from the planting date calculated for this location.
How much frost will melons tolerate?
Melons stop growing below 15C and never fully recover. Frost is fatal, but the real limit is cool nights.