When to plant sweet corn in Missoula
Sweet corn is frost-tender, so every date keys off Missoula's last spring frost of May 15.
Step 1 · Sow
Direct sow outdoors
Jul 2 – Jul 23
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Aug 31 – Oct 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 100 d
Missoula's 138-day season leaves this much room.
Sweet corn 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 sweet corn outdoors in Missoula?
Direct-sow around early July (Jul 2–Jul 23) in Missoula, based on its local frost dates. Confidence 81%.
When will sweet corn be ready to harvest in Missoula?
Expect to harvest from around late August (Aug 31–Oct 10) in Missoula, based on its local frost dates. Confidence 75%.
How long is the growing season in Missoula?
Missoula has roughly 138 frost-free days, which is enough time to grow sweet corn to maturity outdoors.
The rule of thumb
Sow sweet corn 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.