Celery · Soweto, Gauteng, South Africa
When to plant celery in Soweto
Main outdoor window
31 Aug - 21 Sep
The window this page is built around.
Timed from last spring frost
17 August
In Soweto, on your chosen risk.
Ready to pick
19 Nov - 9 Dec
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 Soweto
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
7-28 Jun
Ten weeks before your last frost, under cover or on a windowsill.
Plant out
31 Aug - 21 Sep
Two weeks after your last frost.
Harvest
19 Nov - 9 Dec
Celery through the year
Against the frost risk in Soweto
Why these dates
Start ten weeks before last frost but plant out two weeks after it. Celery exposed to a fortnight below 10C after transplanting will bolt rather than form heads.
Light frost is tolerated at maturity, but cold early in life triggers bolting. This crop is unusual in that too-early planting causes failure without any visible frost damage.
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. Celery are timed from 10 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Soweto.
The median frost-free season here is 292 days, against 80 to 100 days to maturity for this crop counted from planting out. That margin is what decides whether a late sowing is worth attempting.
Also in Soweto
Other vegetables to time
Growing celery in Soweto
When should I plant celery in Soweto?
Aim for 31 Aug - 21 Sep in an average year. If you would rather not gamble on the weather, wait until 15 Sep - 6 Oct - by then frost has finished in nine years out of ten.
When will celery be ready to harvest in Soweto?
Expect to start picking around 19 Nov - 9 Dec, based on 80 to 100 days to maturity from the planting date calculated for this location.
How much frost will celery tolerate?
Light frost is tolerated at maturity, but cold early in life triggers bolting. This crop is unusual in that too-early planting causes failure without any visible frost damage.