Collards · Jiangmen, Guangdong, China
When to plant collards in Jiangmen
Main outdoor window
11 Jan - 8 Feb
The window this page is built around.
Timed from last spring frost
25 January
In Jiangmen, on your chosen risk.
Ready to pick
1 Sep - 31 Mar
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 Jiangmen
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
14 Dec - 11 Jan
Six weeks before your last frost, under cover or on a windowsill.
Sow for overwintering
1-22 Sep
Counting back 89 days from your first frost so the crop matures in time.
Sow direct
11 Jan - 8 Feb
Two weeks before your last frost.
Transplant
11 Jan - 8 Feb
Two weeks before your last frost.
Harvest
1 Sep - 31 Mar
Collards through the year
Against the frost risk in Jiangmen
Why these dates
Sow in spring for summer picking or, better, twelve weeks before the first autumn frost for leaves through winter. Pick the lower leaves and the plant keeps rising.
Survives about -10C and sweetens sharply once night temperatures drop below freezing, which is why southern growers treat frost as the start of the season rather than the end.
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. Collards are timed from 6 weeks before that frost for an indoor start, with planting out 2 weeks before it, and this page simply resolves those offsets against the frost date computed for Jiangmen.
The median frost-free season here is 329 days, against 55 to 75 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Jiangmen
Other vegetables to time
Growing collards in Jiangmen
When should I plant collards in Jiangmen?
Aim for 11 Jan - 8 Feb in an average year. If you would rather not gamble on the weather, wait until 11 Jan - 8 Feb - by then frost has finished in nine years out of ten.
When will collards be ready to harvest in Jiangmen?
Expect to start picking around 1 Sep - 31 Mar, based on 55 to 75 days to maturity from the planting date calculated for this location.
How much frost will collards tolerate?
Survives about -10C and sweetens sharply once night temperatures drop below freezing, which is why southern growers treat frost as the start of the season rather than the end.