When to plant sweet potato in Christchurch
Sweet potato is frost-tender, so every date keys off Christchurch's last spring frost of Oct 10.
Step 1 · Plant
Transplant outdoors
Oct 31 – Nov 21
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Jan 29 – Feb 28
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
Christchurch's 192-day season leaves this much room.
Sweet potato 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 will sweet potato be ready to harvest in Christchurch?
Expect to harvest from around late January (Jan 29–Feb 28) in Christchurch, based on its local frost dates. Confidence 72%.
When can I transplant sweet potato outdoors in Christchurch?
Transplant outdoors around late October (Oct 31–Nov 21) in Christchurch, based on its local frost dates. Confidence 80%.
How long is the growing season in Christchurch?
Christchurch has roughly 192 frost-free days, which is enough time to grow sweet potato to maturity outdoors.
The rule of thumb
Sow sweet potato 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.