When to plant sweet corn in Christchurch
Sweet corn is frost-tender, so every date keys off Christchurch's last spring frost of Oct 10.
Step 1 · Sow
Direct sow outdoors
Oct 17 – Nov 7
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Dec 16 – Jan 25
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 100 d
Christchurch's 192-day season leaves this much room.
Sweet corn on Christchurch's growing year
Frost-bounded season with crops mapped onto the 12-month axis.
Frost risk Growing Harvest
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
FROST
OCT 10
APR 20
Common questions
When can I sow sweet corn outdoors in Christchurch?
Direct-sow around mid October (Oct 17–Nov 7) in Christchurch, based on its local frost dates. Confidence 80%.
When will sweet corn be ready to harvest in Christchurch?
Expect to harvest from around mid December (Dec 16–Jan 25) in Christchurch, based on its local frost dates. Confidence 72%.
How long is the growing season in Christchurch?
Christchurch has roughly 192 frost-free days, which is enough time to grow sweet corn to maturity outdoors.
The rule of thumb
Sow sweet corn 6–8 weeks before your last spring frost; plant out 2–3 weeks after it. Every date on this page is derived from that rule and Christchurch's frost dates.
Confidence 80/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.