When to plant Sweet corn in Colorado

In spring, from Apr 10 – June 1 in Grand Junction to May 15 – June 1 in Monument.

In fall, June 1 – July 1.

USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.

Sweet corn planting dates by place in Colorado
PlaceSpringFall
ArvadaMay 10 – June 15June 1 – July 1
AuroraMay 10 – June 1June 1 – July 10
BerthoudMay 10 – June 1June 1 – July 1
BoulderMay 10 – June 1June 1 – July 1
BrightonMay 10 – June 15June 1 – July 10
BroomfieldMay 10 – June 15June 1 – July 10
Cañon CityMay 10 – June 15June 1 – July 10
Castle PinesMay 10 – June 1June 1 – July 1
Castle RockMay 10 – June 1June 1 – July 1
CentennialMay 10 – June 15June 1 – July 10
Colorado SpringsMay 10 – June 15June 1 – July 10
Commerce CityMay 10 – June 15June 1 – July 10
DenverMay 10 – June 15June 1 – July 10
DurangoMay 15 – June 1June 1 – July 1
EnglewoodMay 10 – June 15June 1 – July 10
ErieMay 10 – June 1June 1 – July 1
EvansMay 10 – June 15June 1 – July 10
Federal HeightsMay 10 – June 15June 1 – July 10
FirestoneMay 10 – June 1June 1 – July 1
Fort CollinsMay 10 – June 15June 1 – July 10
Fort MorganMay 10 – June 1June 1 – July 10
FountainMay 10 – June 15June 1 – July 10
FrederickMay 10 – June 1June 1 – July 1
FruitaMay 10 – June 15June 1 – July 10
Glenwood SpringsMay 10 – June 1June 1 – July 1
GoldenMay 10 – June 15June 1 – July 10
Grand JunctionApr 10 – June 1June 1 – July 20
GreeleyMay 10 – June 15June 1 – July 10
Greenwood VillageMay 10 – June 1June 1 – July 10
JohnstownMay 10 – June 1June 1 – July 1
LafayetteMay 10 – June 15June 1 – July 10
LakewoodMay 10 – June 15June 1 – July 10
LittletonMay 10 – June 15June 1 – July 10
Lone TreeMay 10 – June 15June 1 – July 10
LongmontMay 10 – June 1June 1 – July 1
LouisvilleMay 10 – June 1June 1 – July 1
LovelandMay 10 – June 1June 1 – July 1
MontroseMay 10 – June 15June 1 – July 10
MonumentMay 15 – June 1June 1 – July 1
NorthglennMay 10 – June 15June 1 – July 10
ParkerMay 10 – June 1June 1 – July 1
PuebloMay 10 – June 15June 1 – July 10
RifleMay 10 – June 1June 1 – July 1
SeveranceMay 10 – June 15June 1 – July 10
Steamboat SpringsNot listedNot listed
SterlingMay 10 – June 15June 1 – July 10
SuperiorMay 10 – June 1June 1 – July 1
ThorntonMay 10 – June 15June 1 – July 10
TimnathMay 10 – June 15June 1 – July 10
WellingtonMay 10 – June 15June 1 – July 10
WestminsterMay 10 – June 15June 1 – July 10
Wheat RidgeMay 10 – June 15June 1 – July 1
WindsorMay 10 – June 15June 1 – July 10

Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. “—” means the place's frost date is outside the table. The full USDA table for sweet corn.