When to plant Brussels sprouts in Colorado

In spring, from Mar 15 – Apr 15 in Grand Junction to May 20 – June 10 in Steamboat Springs.

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

Brussels sprouts planting dates by place in Colorado
PlaceSpringFall
ArvadaApr 1 – May 1June 1 – 30
AuroraApr 15 – June 1June 15 – July 15
BerthoudApr 15 – June 1June 1 – 30
BoulderApr 15 – June 1June 1 – 30
BrightonApr 1 – May 1June 15 – July 15
BroomfieldApr 1 – May 1June 15 – July 15
Cañon CityApr 1 – May 1June 15 – July 15
Castle PinesApr 15 – June 1June 1 – 30
Castle RockApr 15 – June 1June 1 – 30
CentennialApr 1 – May 1June 15 – July 15
Colorado SpringsApr 1 – May 1June 15 – July 15
Commerce CityApr 1 – May 1June 15 – July 15
DenverApr 1 – May 1June 15 – July 15
DurangoMay 1 – June 15June 1 – 30
EnglewoodApr 1 – May 1June 15 – July 15
ErieApr 15 – June 1June 1 – 30
EvansApr 1 – May 1June 15 – July 15
Federal HeightsApr 1 – May 1June 15 – July 15
FirestoneApr 15 – June 1June 1 – 30
Fort CollinsApr 1 – May 1June 15 – July 15
Fort MorganApr 15 – June 1June 15 – July 15
FountainApr 1 – May 1June 15 – July 15
FrederickApr 15 – June 1June 1 – 30
FruitaApr 1 – May 1June 15 – July 15
Glenwood SpringsApr 15 – June 1June 1 – 30
GoldenApr 1 – May 1June 15 – July 15
Grand JunctionMar 15 – Apr 15July 1 – Aug 1
GreeleyApr 1 – May 1June 15 – July 15
Greenwood VillageApr 15 – June 1June 15 – July 15
JohnstownApr 15 – June 1June 1 – 30
LafayetteApr 1 – May 1June 15 – July 15
LakewoodApr 1 – May 1June 15 – July 15
LittletonApr 1 – May 1June 15 – July 15
Lone TreeApr 1 – May 1June 15 – July 15
LongmontApr 15 – June 1June 1 – 30
LouisvilleApr 15 – June 1June 1 – 30
LovelandApr 15 – June 1June 1 – 30
MontroseApr 1 – May 1June 15 – July 15
MonumentMay 1 – June 15June 1 – 30
NorthglennApr 1 – May 1June 15 – July 15
ParkerApr 15 – June 1June 1 – 30
PuebloApr 1 – May 1June 15 – July 15
RifleApr 15 – June 1June 1 – 30
SeveranceApr 1 – May 1June 15 – July 15
Steamboat SpringsMay 20 – June 10May 1 – June 1
SterlingApr 1 – May 1June 15 – July 15
SuperiorApr 15 – June 1June 1 – 30
ThorntonApr 1 – May 1June 15 – July 15
TimnathApr 1 – May 1June 15 – July 15
WellingtonApr 1 – May 1June 15 – July 15
WestminsterApr 1 – May 1June 15 – July 15
Wheat RidgeApr 1 – May 1June 1 – 30
WindsorApr 1 – May 1June 15 – July 15

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 brussels sprouts.