When to plant broccoli in Colorado

Broccoli
Plant out in Denver
Apr 6–Apr 20

Across Colorado the window opens between March 17 and April 12. 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 6–Apr 20
Fall planting, Denver
Jul 16–Jul 30
Last frost, Denver
May 4

Start seeds indoors 8–10 weeks before the last frost; plant out 2–4 weeks before the last frost; sow again for fall 10–12 weeks before the first frost. Broccoli grown for a fall harvest often tastes sweeter than spring broccoli. Light frost improves it.

Broccoli planting dates by city

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

Questions

When should I plant broccoli in Colorado?

In Denver, plant out from April 6 to April 20. Across Colorado the window opens between March 17 and April 12, depending on the local last frost.

How is this date worked out?

Start seeds indoors 8–10 weeks before the last frost; plant out 2–4 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

Broccoli in other states

Frost dates for every city in Colorado