Potato · Yanghang, Shanghai, China
When to plant potatoes in Yanghang
Main outdoor window
17 Feb - 3 Mar
The window this page is built around.
Timed from last spring frost
3 March
In Yanghang, on your chosen risk.
Ready to pick
28 Apr - 17 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 Yanghang
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 direct
17 Feb - 3 Mar
Two weeks before your last frost.
Harvest
28 Apr - 17 Jun
Potatoes through the year
Against the frost risk in Yanghang
Why these dates
Plant two weeks before last frost so shoots emerge around the frost date. Earthing up buries vulnerable shoots and buys you a week of frost protection at a time.
Emerged foliage is blackened at -2C, though the plant usually regrows from the tuber with a yield penalty. Frost after emergence is the classic potato setback.
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. Potatoes are timed for direct sowing 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Yanghang.
The median frost-free season here is 286 days, against 70 to 120 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Yanghang
Other vegetables to time
Growing potatoes in Yanghang
When should I plant potatoes in Yanghang?
Aim for 17 Feb - 3 Mar in an average year. If you would rather not gamble on the weather, wait until 28 Feb - 14 Mar - by then frost has finished in nine years out of ten.
When will potatoes be ready to harvest in Yanghang?
Expect to start picking around 28 Apr - 17 Jun, based on 70 to 120 days to maturity from the planting date calculated for this location.
How much frost will potatoes tolerate?
Emerged foliage is blackened at -2C, though the plant usually regrows from the tuber with a yield penalty. Frost after emergence is the classic potato setback.