When to plant summer squash / zucchini in Winnipeg

Summer squash / Zucchini is frost-tender, so every date keys off Winnipeg's last spring frost of May 25.
Step 1 · Sow
Start seeds indoors
May 11 – Jun 1
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Jun 1 – Jun 22
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 16 – Jul 31
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Winnipeg's 118-day season leaves this much room.
Summer squash / Zucchini on Winnipeg'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
MAY 25
SEP 20

Common questions

When can I sow summer squash / zucchini outdoors in Winnipeg?

Direct-sow around early June (Jun 1–Jun 22) in Winnipeg, based on its local frost dates. Confidence 72%.

When will summer squash / zucchini be ready to harvest in Winnipeg?

Expect to harvest from around mid July (Jul 16–Jul 31) in Winnipeg, based on its local frost dates. Confidence 65%.

When should I start summer squash / zucchini seeds indoors in Winnipeg?

Start seeds indoors around mid May (May 11–Jun 1) in Winnipeg, based on its local frost dates. Confidence 68%.

When can I transplant summer squash / zucchini outdoors in Winnipeg?

Transplant outdoors around early June (Jun 1–Jun 22) in Winnipeg, based on its local frost dates. Confidence 72%.

How long is the growing season in Winnipeg?

Winnipeg has roughly 118 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 Winnipeg's frost dates.

Confidence 72/100 · NASA POWER (modeled) · 1991–2020 · frost dates are probabilities, not guarantees.