When to plant Collard greens in Colorado

In spring, from Mar 1 – June 1 in Grand Junction to May 20 – June 1 in Steamboat Springs.

In fall, from May 15 – June 15 in Steamboat Springs to July 15 – Aug 15 in Grand Junction.

Dates are for setting out plants. USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.

Collards planting dates by place in Colorado
PlaceSpringFall
ArvadaApr 1 – June 1June 15 – July 15
AuroraApr 15 – June 1July 1 – Aug 1
BerthoudApr 15 – June 1June 15 – July 15
BoulderApr 15 – June 1June 15 – July 15
BrightonApr 1 – June 1July 1 – Aug 1
BroomfieldApr 1 – June 1July 1 – Aug 1
Cañon CityApr 1 – June 1July 1 – Aug 1
Castle PinesApr 15 – June 1June 15 – July 15
Castle RockApr 15 – June 1June 15 – July 15
CentennialApr 1 – June 1July 1 – Aug 1
Colorado SpringsApr 1 – June 1July 1 – Aug 1
Commerce CityApr 1 – June 1July 1 – Aug 1
DenverApr 1 – June 1July 1 – Aug 1
DurangoMay 1 – June 1June 15 – July 15
EnglewoodApr 1 – June 1July 1 – Aug 1
ErieApr 15 – June 1June 15 – July 15
EvansApr 1 – June 1July 1 – Aug 1
Federal HeightsApr 1 – June 1July 1 – Aug 1
FirestoneApr 15 – June 1June 15 – July 15
Fort CollinsApr 1 – June 1July 1 – Aug 1
Fort MorganApr 15 – June 1July 1 – Aug 1
FountainApr 1 – June 1July 1 – Aug 1
FrederickApr 15 – June 1June 15 – July 15
FruitaApr 1 – June 1July 1 – Aug 1
Glenwood SpringsApr 15 – June 1June 15 – July 15
GoldenApr 1 – June 1July 1 – Aug 1
Grand JunctionMar 1 – June 1July 15 – Aug 15
GreeleyApr 1 – June 1July 1 – Aug 1
Greenwood VillageApr 15 – June 1July 1 – Aug 1
JohnstownApr 15 – June 1June 15 – July 15
LafayetteApr 1 – June 1July 1 – Aug 1
LakewoodApr 1 – June 1July 1 – Aug 1
LittletonApr 1 – June 1July 1 – Aug 1
Lone TreeApr 1 – June 1July 1 – Aug 1
LongmontApr 15 – June 1June 15 – July 15
LouisvilleApr 15 – June 1June 15 – July 15
LovelandApr 15 – June 1June 15 – July 15
MontroseApr 1 – June 1July 1 – Aug 1
MonumentMay 1 – June 1June 15 – July 15
NorthglennApr 1 – June 1July 1 – Aug 1
ParkerApr 15 – June 1June 15 – July 15
PuebloApr 1 – June 1July 1 – Aug 1
RifleApr 15 – June 1June 15 – July 15
SeveranceApr 1 – June 1July 1 – Aug 1
Steamboat SpringsMay 20 – June 1May 15 – June 15
SterlingApr 1 – June 1July 1 – Aug 1
SuperiorApr 15 – June 1June 15 – July 15
ThorntonApr 1 – June 1July 1 – Aug 1
TimnathApr 1 – June 1July 1 – Aug 1
WellingtonApr 1 – June 1July 1 – Aug 1
WestminsterApr 1 – June 1July 1 – Aug 1
Wheat RidgeApr 1 – June 1June 15 – July 15
WindsorApr 1 – June 1July 1 – Aug 1

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 collards.