When to plant summer squash / zucchini in Sapporo
Summer squash / Zucchini is frost-tender, so every date keys off Sapporo's last spring frost of May 12.
Step 1 · Sow
Start seeds indoors
May 5 – May 26
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Jul 2 – Jul 23
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Aug 16 – Aug 31
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Sapporo's 166-day season leaves this much room.
Summer squash / Zucchini 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 can I sow summer squash / zucchini outdoors in Sapporo?
Direct-sow around early July (Jul 2–Jul 23) in Sapporo, based on its local frost dates. Confidence 44%.
When will summer squash / zucchini be ready to harvest in Sapporo?
Expect to harvest from around mid August (Aug 16–Aug 31) in Sapporo, based on its local frost dates. Confidence 40%.
When should I start summer squash / zucchini seeds indoors in Sapporo?
Start seeds indoors around early May (May 5–May 26) in Sapporo, based on its local frost dates. Confidence 43%.
When can I transplant summer squash / zucchini outdoors in Sapporo?
Transplant outdoors around early July (Jul 2–Jul 23) 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 summer squash / zucchini to maturity outdoors.
The rule of thumb
Sow summer squash / zucchini 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.