When to plant sweet corn in Duluth
Sweet corn is frost-tender, so every date keys off Duluth's last spring frost of May 10.
Step 1 · Sow
Direct sow outdoors
Jul 3 – Jul 24
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Sep 1 – Oct 11
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 100 d
Duluth's 150-day season leaves this much room.
Sweet corn on Duluth'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 10
OCT 7
Common questions
When can I sow sweet corn outdoors in Duluth?
Direct-sow around early July (Jul 3–Jul 24) in Duluth, based on its local frost dates. Confidence 84%.
When will sweet corn be ready to harvest in Duluth?
Expect to harvest from around early September (Sep 1–Oct 11) in Duluth, based on its local frost dates. Confidence 78%.
How long is the growing season in Duluth?
Duluth has roughly 150 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 Duluth's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.