When to plant winter squash / pumpkin in Missoula
Winter squash / Pumpkin is frost-tender, so every date keys off Missoula's last spring frost of May 15.
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
Sep 25 – Oct 30
Picking runs until conditions turn against the crop.
Window
Days to maturity
85 – 120 d
Missoula's 138-day season leaves this much room.
Winter squash / Pumpkin on Missoula'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
HARVEST
MAY 15
OCT 4
Common questions
When can I sow winter squash / pumpkin outdoors in Missoula?
Direct-sow around early July (Jul 2–Jul 23) in Missoula, based on its local frost dates. Confidence 81%.
When will winter squash / pumpkin be ready to harvest in Missoula?
Expect to harvest from around late September (Sep 25–Oct 30) in Missoula, based on its local frost dates. Confidence 75%.
When should I start winter squash / pumpkin seeds indoors in Missoula?
Start seeds indoors around early May (May 5–May 26) in Missoula, based on its local frost dates. Confidence 79%.
When can I transplant winter squash / pumpkin outdoors in Missoula?
Transplant outdoors around early July (Jul 2–Jul 23) in Missoula, based on its local frost dates. Confidence 81%.
How long is the growing season in Missoula?
Missoula has roughly 138 frost-free days, which is enough time to grow winter squash / pumpkin to maturity outdoors.
The rule of thumb
Sow winter squash / pumpkin 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 Missoula's frost dates.
Confidence 83/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.