When to plant sweet potato in Sapporo
Sweet potato is frost-tender, so every date keys off Sapporo's last spring frost of May 12.
Step 1 · Plant
Transplant outdoors
Jul 18 – Aug 8
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Oct 16 – Nov 15
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
Sapporo's 166-day season leaves this much room.
Sweet potato on Sapporo'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
FROST
MAY 12
OCT 20
Common questions
When will sweet potato be ready to harvest in Sapporo?
Expect to harvest from around mid October (Oct 16–Nov 15) in Sapporo, based on its local frost dates. Confidence 40%.
When can I transplant sweet potato outdoors in Sapporo?
Transplant outdoors around mid July (Jul 18–Aug 8) in Sapporo, based on its local frost dates. Confidence 44%.
How long is the growing season in Sapporo?
Sapporo has roughly 166 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 Sapporo's frost dates.
Confidence 45/100 · Curated · based on NASA POWER (modeled) 1991–2020 · frost dates are probabilities, not guarantees.