Potato · Zigong, Sichuan, China
When to plant potatoes in Zigong
Main outdoor window
20 Jan - 3 Feb
The window this page is built around.
Timed from last spring frost
3 February
In Zigong, on your chosen risk.
Ready to pick
31 Mar - 20 May
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 Zigong
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
20 Jan - 3 Feb
Two weeks before your last frost.
Harvest
31 Mar - 20 May
Potatoes through the year
Against the frost risk in Zigong
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 Zigong.
The median frost-free season here is 318 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 Zigong
Other vegetables to time
Growing potatoes in Zigong
When should I plant potatoes in Zigong?
Aim for 20 Jan - 3 Feb in an average year. If you would rather not gamble on the weather, wait until 7-21 Feb - by then frost has finished in nine years out of ten.
When will potatoes be ready to harvest in Zigong?
Expect to start picking around 31 Mar - 20 May, 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.