When to plant cauliflower in Colorado

Cauliflower
Plant out in Denver
Apr 20–May 4

Across Colorado the window opens between March 31 and April 26. Find your city below; the dates follow each town's own average last frost.

Start indoors, Denver
Feb 23–Mar 9
Plant out, Denver
Apr 20–May 4
Fall planting, Denver
Jul 16–Jul 30
Last frost, Denver
May 4

Start seeds indoors 8–10 weeks before the last frost; plant out up to 2 weeks before the last frost; sow again for fall 10–12 weeks before the first frost. When heads reach the size of an egg, tie the leaves over them to keep them white.

Cauliflower planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
JanFebMarAprMayJunJulAugSepOctNovDec
DenverApr 20–May 4
Colorado SpringsApr 19–May 3
AuroraApr 23–May 7
Fort CollinsApr 18–May 2
LakewoodApr 19–May 3
ThorntonApr 18–May 2
ArvadaApr 21–May 5
WestminsterApr 18–May 2
GreeleyApr 18–May 2
PuebloApr 16–Apr 30
CentennialApr 21–May 5
BoulderApr 22–May 6
LongmontApr 23–May 7
LovelandApr 26–May 10
BroomfieldApr 18–May 2
Commerce CityApr 19–May 3
Grand JunctionMar 31–Apr 14
LittletonApr 18–May 2
BrightonApr 19–May 3
WindsorApr 19–May 3
ErieApr 23–May 7
NorthglennApr 18–May 2
Security-WidefieldApr 19–May 3
EnglewoodApr 18–May 2
Pueblo WestApr 12–Apr 26
Wheat RidgeApr 21–May 5
LafayetteApr 18–May 2
FountainApr 19–May 3
EvansApr 18–May 2
JohnstownApr 26–May 10
All 34 cities
CityStart indoorsPlant outFall plantingLast frost
DenverFeb 23 to Mar 9Apr 20 to May 4Jul 16 to Jul 30May 4
Colorado SpringsFeb 22 to Mar 8Apr 19 to May 3Jul 16 to Jul 30May 3
AuroraFeb 26 to Mar 12Apr 23 to May 7Jul 16 to Jul 30May 7
Fort CollinsFeb 21 to Mar 7Apr 18 to May 2Jul 15 to Jul 29May 2
LakewoodFeb 22 to Mar 8Apr 19 to May 3Jul 15 to Jul 29May 3
ThorntonFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
ArvadaFeb 24 to Mar 10Apr 21 to May 5Jul 13 to Jul 27May 5
WestminsterFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
GreeleyFeb 21 to Mar 7Apr 18 to May 2Jul 16 to Jul 30May 2
PuebloFeb 19 to Mar 5Apr 16 to Apr 30Jul 17 to Jul 31Apr 30
CentennialFeb 24 to Mar 10Apr 21 to May 5Jul 16 to Jul 30May 5
BoulderFeb 25 to Mar 11Apr 22 to May 6Jul 13 to Jul 27May 6
LongmontFeb 26 to Mar 12Apr 23 to May 7Jul 13 to Jul 27May 7
LovelandMar 1 to Mar 15Apr 26 to May 10May 10
BroomfieldFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
Commerce CityFeb 22 to Mar 8Apr 19 to May 3Jul 15 to Jul 29May 3
Grand JunctionFeb 3 to Feb 17Mar 31 to Apr 14Jul 31 to Aug 14Apr 14
LittletonFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
BrightonFeb 22 to Mar 8Apr 19 to May 3Jul 15 to Jul 29May 3
WindsorFeb 22 to Mar 8Apr 19 to May 3Jul 14 to Jul 28May 3
ErieFeb 26 to Mar 12Apr 23 to May 7Jul 13 to Jul 27May 7
NorthglennFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
Security-WidefieldFeb 22 to Mar 8Apr 19 to May 3Jul 16 to Jul 30May 3
EnglewoodFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
Pueblo WestFeb 15 to Mar 1Apr 12 to Apr 26Jul 21 to Aug 4Apr 26
Wheat RidgeFeb 24 to Mar 10Apr 21 to May 5Jul 13 to Jul 27May 5
LafayetteFeb 21 to Mar 7Apr 18 to May 2Jul 19 to Aug 2May 2
FountainFeb 22 to Mar 8Apr 19 to May 3Jul 16 to Jul 30May 3
EvansFeb 21 to Mar 7Apr 18 to May 2Jul 16 to Jul 30May 2
JohnstownMar 1 to Mar 15Apr 26 to May 10May 10
Four Square MileFeb 26 to Mar 12Apr 23 to May 7Jul 16 to Jul 30May 7
MontroseFeb 17 to Mar 3Apr 14 to Apr 28Jul 22 to Aug 5Apr 28
LouisvilleFeb 25 to Mar 11Apr 22 to May 6Jul 13 to Jul 27May 6
FirestoneFeb 26 to Mar 12Apr 23 to May 7Jul 13 to Jul 27May 7

Questions

When should I plant cauliflower in Colorado?

In Denver, plant out from April 20 to May 4. Across Colorado the window opens between March 31 and April 26, depending on the local last frost.

How is this date worked out?

Start seeds indoors 8–10 weeks before the last frost; plant out up to 2 weeks before the last frost; sow again for fall 10–12 weeks before the first frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Colorado

Cauliflower in other states

Frost dates for every city in Colorado