Sea kale · Shanghai, Shanghai, China
When to plant sea kale in Shanghai
Main outdoor window
13 Dec - 16 Feb
The window this page is built around.
Timed from last spring frost
2 March
In Shanghai, on your chosen risk.
Ready to pick
1 Mar - 31 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 Shanghai
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.
Plant out
13 Dec - 16 Feb
Any time the plant is dormant and the ground is neither frozen nor waterlogged: after leaf fall in autumn, or at the end of winter before growth restarts.
Harvest
1 Mar - 31 May
Sea kale through the year
Against the frost risk in Shanghai
Why these dates
Very hardy, to -20C, and tolerant of salt spray and sand.
Sea kale are planted once and then left in place, so there is no sowing offset to resolve. What matters in Shanghai is the shape of the year: this crop is dormant through the winter and is planted while it sleeps, any time between leaf fall in autumn and the restart of growth in spring, so long as the ground is neither frozen nor waterlogged. That is why the window below spans the cold months rather than sitting in the middle of the growing season.
Shanghai sits in zone 9a, which is milder than this crop wants, and a winter that never really arrives is its own problem. The dates below still describe the right time of year; the open question is survival rather than timing.
Do not expect a crop in the first year. A plant set out now should give its first worthwhile pick around year 2, and will then produce every year after that, which is what makes the planting decision worth getting right the first time.
Also in Shanghai
Other vegetables to time
Growing sea kale in Shanghai
When should I plant sea kale in Shanghai?
Aim for 13 Dec - 16 Feb in an average year. If you would rather not gamble on the weather, wait until 25 Nov - 28 Feb - by then frost has finished in nine years out of ten.
When will sea kale be ready to harvest in Shanghai?
Expect to start picking around 1 Mar - 31 May, based on 90 to 120 days to maturity from the planting date calculated for this location.
How much frost will sea kale tolerate?
Very hardy, to -20C, and tolerant of salt spray and sand.