Leek · Zhenjiang, Jiangsu, China
When to plant leeks in Zhenjiang
Main outdoor window
19 Mar - 9 Apr
The window this page is built around.
Timed from last spring frost
19 March
In Zhenjiang, on your chosen risk.
Ready to pick
27 Jun - 17 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 Zhenjiang
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
22 Jan - 12 Feb
Eight weeks before your last frost, under cover or on a windowsill.
Plant out
19 Mar - 9 Apr
Around your last frost.
Harvest
27 Jun - 17 Jul
Leeks through the year
Against the frost risk in Zhenjiang
Why these dates
Sow indoors eight weeks before last frost, transplant around the frost date into deep holes. Harvest from autumn right through to spring as needed.
Hardy to -15C and often the only fresh vegetable still standing in midwinter.
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. Leeks are timed from 8 weeks before that frost for an indoor start, with planting out 0 weeks after it, and this page simply resolves those offsets against the frost date computed for Zhenjiang.
The median frost-free season here is 252 days, against 100 to 120 days to maturity for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Zhenjiang
Other vegetables to time
Growing leeks in Zhenjiang
When should I plant leeks in Zhenjiang?
Aim for 19 Mar - 9 Apr in an average year. If you would rather not gamble on the weather, wait until 30 Mar - 20 Apr - by then frost has finished in nine years out of ten.
When will leeks be ready to harvest in Zhenjiang?
Expect to start picking around 27 Jun - 17 Jul, based on 100 to 120 days to maturity from the planting date calculated for this location.
How much frost will leeks tolerate?
Hardy to -15C and often the only fresh vegetable still standing in midwinter.