Calla lily · Pretoria, Gauteng, South Africa
When to sow calla lilies in Pretoria
Main outdoor window
31 Jul - 28 Aug
The window this page is built around.
Timed from last spring frost
24 July
In Pretoria, on your chosen risk.
Ready to pick
29 Nov - 28 Feb
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 Pretoria
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 the rhizomes
31 Jul - 28 Aug
After the last frost, once the soil has warmed. This crop is never fully dormant, so it cannot be planted bare-root in winter.
In flower
29 Nov - 28 Feb
Calla lilies through the year
Against the frost risk in Pretoria
Why these dates
Plant a week after the last frost, 8cm deep, and water generously - this is one of the few plants here that cannot be overwatered in summer. In zone 8 and warmer it can be left in the ground and treated as an ordinary perennial.
Hardy to about -5C with a mulch, and the white-flowered species is the toughest of the group; the coloured hybrids are appreciably more tender. Below zone 8 lift and store the rhizomes, or overwinter the pot dry under cover.
Calla lilies are planted once and then left in place, so there is no sowing offset to resolve. Nor is there a dormant season to plant into: this crop keeps its leaves and keeps growing through the winter, which is exactly why cold damages it. The window on this page therefore waits until the last frost in Pretoria has passed and the soil has begun to warm, giving the roots the longest possible run before the cold returns.
Hardiness is not the obstacle here. Pretoria is zone 10a, comfortably inside the range this crop is rated for, so an established plant should come through an average winter without protection.
Also in Pretoria
Other flowers to time
Growing calla lilies in Pretoria
When should I plant calla lilies in Pretoria?
Aim for 31 Jul - 28 Aug in an average year. If you would rather not gamble on the weather, wait until 17 Aug - 14 Sep - by then frost has finished in nine years out of ten.
When will calla lilies be ready to harvest in Pretoria?
Expect to start picking around 29 Nov - 28 Feb, based on 100 to 130 days to maturity from the planting date calculated for this location.
How much frost will calla lilies tolerate?
Hardy to about -5C with a mulch, and the white-flowered species is the toughest of the group; the coloured hybrids are appreciably more tender. Below zone 8 lift and store the rhizomes, or overwinter the pot dry under cover.