When to plant Swiss chard in Colorado

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

In fall, from May 15 – July 1 in Steamboat Springs to June 1 – July 20 in Windsor.

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

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

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 swiss chard.