When to plant Cauliflower in Colorado

In spring, from Mar 1 – 20 in Grand Junction to June 1 – 15 in Steamboat Springs.

In fall, from May 1 – July 1 in Steamboat Springs to July 1 – Aug 5 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.

Cauliflower planting dates by place in Colorado
PlaceSpringFall
ArvadaApr 10 – May 10May 10 – July 15
AuroraApr 15 – May 15June 1 – July 25
BerthoudApr 15 – May 15May 10 – July 15
BoulderApr 15 – May 15May 10 – July 15
BrightonApr 10 – May 10June 1 – July 25
BroomfieldApr 10 – May 10June 1 – July 25
Cañon CityApr 10 – May 10June 1 – July 25
Castle PinesApr 15 – May 15May 10 – July 15
Castle RockApr 15 – May 15May 10 – July 15
CentennialApr 10 – May 10June 1 – July 25
Colorado SpringsApr 10 – May 10June 1 – July 25
Commerce CityApr 10 – May 10June 1 – July 25
DenverApr 10 – May 10June 1 – July 25
DurangoMay 10 – June 15May 10 – July 15
EnglewoodApr 10 – May 10June 1 – July 25
ErieApr 15 – May 15May 10 – July 15
EvansApr 10 – May 10June 1 – July 25
Federal HeightsApr 10 – May 10June 1 – July 25
FirestoneApr 15 – May 15May 10 – July 15
Fort CollinsApr 10 – May 10June 1 – July 25
Fort MorganApr 15 – May 15June 1 – July 25
FountainApr 10 – May 10June 1 – July 25
FrederickApr 15 – May 15May 10 – July 15
FruitaApr 10 – May 10June 1 – July 25
Glenwood SpringsApr 15 – May 15May 10 – July 15
GoldenApr 10 – May 10June 1 – July 25
Grand JunctionMar 1 – 20July 1 – Aug 5
GreeleyApr 10 – May 10June 1 – July 25
Greenwood VillageApr 15 – May 15June 1 – July 25
JohnstownApr 15 – May 15May 10 – July 15
LafayetteApr 10 – May 10June 1 – July 25
LakewoodApr 10 – May 10June 1 – July 25
LittletonApr 10 – May 10June 1 – July 25
Lone TreeApr 10 – May 10June 1 – July 25
LongmontApr 15 – May 15May 10 – July 15
LouisvilleApr 15 – May 15May 10 – July 15
LovelandApr 15 – May 15May 10 – July 15
MontroseApr 10 – May 10June 1 – July 25
MonumentMay 10 – June 15May 10 – July 15
NorthglennApr 10 – May 10June 1 – July 25
ParkerApr 15 – May 15May 10 – July 15
PuebloApr 10 – May 10June 1 – July 25
RifleApr 15 – May 15May 10 – July 15
SeveranceApr 10 – May 10June 1 – July 25
Steamboat SpringsJune 1 – 15May 1 – July 1
SterlingApr 10 – May 10June 1 – July 25
SuperiorApr 15 – May 15May 10 – July 15
ThorntonApr 10 – May 10June 1 – July 25
TimnathApr 10 – May 10June 1 – July 25
WellingtonApr 10 – May 10June 1 – July 25
WestminsterApr 10 – May 10June 1 – July 25
Wheat RidgeApr 10 – May 10May 10 – July 15
WindsorApr 10 – May 10June 1 – July 25

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 cauliflower.