Safe to Plant

Calla lily · Ciudad Nezahualcoyotl, México, Mexico

When to sow calla lilies in Ciudad Nezahualcoyotl

Main outdoor window

16 Feb - 16 Mar

The window this page is built around.

Timed from last spring frost

9 February

In Ciudad Nezahualcoyotl, on your chosen risk.

Ready to pick

1 Jun - 31 Aug

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 Ciudad Nezahualcoyotl

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

16 Feb - 16 Mar

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

1 Jun - 31 Aug

Frost tolerance
Half-hardy
Damaged below
-5°C (23°F)
Hardy to
Zone 8a–11a
Min soil temp
12°C (53.6°F)
Spacing
40 cm
Sowing depth
80 mm (3.1 in)
Sun
Partial

Calla lilies through the year

Against the frost risk in Ciudad Nezahualcoyotl

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Frost risk Plant Harvest Today

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 Ciudad Nezahualcoyotl 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. Ciudad Nezahualcoyotl is zone 9b, comfortably inside the range this crop is rated for, so an established plant should come through an average winter without protection.

See every crop timed for Ciudad Nezahualcoyotl →

Growing calla lilies in Ciudad Nezahualcoyotl

When should I plant calla lilies in Ciudad Nezahualcoyotl?

Aim for 16 Feb - 16 Mar in an average year. If you would rather not gamble on the weather, wait until 7 Mar - 4 Apr - by then frost has finished in nine years out of ten.

When will calla lilies be ready to harvest in Ciudad Nezahualcoyotl?

Expect to start picking around 1 Jun - 31 Aug, 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.