FrostCal

When to Plant Broccoli in Colorado

In a typical Colorado location, start seeds indoors Mar 15 – Mar 29, then transplant outdoors Apr 12 – Apr 19. Across the state, the outdoor planting window starts as early as Mar 24 in Grand Junction and as late as May 31 in Edwards. For a fall crop, plant around Aug 6 – Aug 13.

Method Start indoors, then transplant
Days to maturity 55–80 days

Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost).

Broccoli Planting Dates by City

CityStart indoorsTransplantFall planting
DenverMar 12 – Mar 26Apr 9 – Apr 16Aug 10 – Aug 17
Colorado SpringsMar 15 – Mar 29Apr 12 – Apr 19Aug 6 – Aug 13
AuroraMar 16 – Mar 30Apr 13 – Apr 20Aug 6 – Aug 13
Fort CollinsMar 14 – Mar 28Apr 11 – Apr 18Aug 5 – Aug 12
LakewoodMar 15 – Mar 29Apr 12 – Apr 19Aug 5 – Aug 12
ThorntonMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
WestminsterMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
ArvadaMar 17 – Mar 31Apr 14 – Apr 21Aug 3 – Aug 10
CentennialMar 17 – Mar 31Apr 14 – Apr 21Aug 6 – Aug 13
PuebloMar 12 – Mar 26Apr 9 – Apr 16Aug 7 – Aug 14
GreeleyMar 14 – Mar 28Apr 11 – Apr 18Aug 6 – Aug 13
BoulderMar 18 – Apr 1Apr 15 – Apr 22Aug 3 – Aug 10
Highlands RanchMar 17 – Mar 31Apr 14 – Apr 21Aug 6 – Aug 13
LongmontMar 19 – Apr 2Apr 16 – Apr 23Aug 3 – Aug 10
LovelandMar 22 – Apr 5Apr 19 – Apr 26Jul 30 – Aug 6
BroomfieldMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
Grand JunctionFeb 24 – Mar 10Mar 24 – Mar 31Aug 21 – Aug 28
Castle RockMar 21 – Apr 4Apr 18 – Apr 25Jul 31 – Aug 7
Commerce CityMar 16 – Mar 30Apr 13 – Apr 20Aug 6 – Aug 13
ParkerMar 21 – Apr 4Apr 18 – Apr 25Aug 1 – Aug 8
LittletonMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
NorthglennMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
BrightonMar 15 – Mar 29Apr 12 – Apr 19Aug 5 – Aug 12
Dakota RidgeMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
EnglewoodMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
Security-WidefieldMar 15 – Mar 29Apr 12 – Apr 19Aug 6 – Aug 13
WindsorMar 15 – Mar 29Apr 12 – Apr 19Aug 4 – Aug 11
Ken CarylMar 14 – Mar 28Apr 11 – Apr 18Aug 9 – Aug 16
Wheat RidgeMar 17 – Mar 31Apr 14 – Apr 21Aug 3 – Aug 10
Pueblo WestMar 8 – Mar 22Apr 5 – Apr 12Aug 11 – Aug 18

Showing the 30 most populous of 65 Colorado cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Colorado cities.

Frequently Asked Questions

When should I plant broccoli in Colorado?

In a typical Colorado location, start seeds indoors Mar 15 – Mar 29, then transplant outdoors Apr 12 – Apr 19. Across the state, the outdoor planting window starts as early as Mar 24 in Grand Junction and as late as May 31 in Edwards. For a fall crop, plant around Aug 6 – Aug 13.

When is the last frost in Colorado?

The average last spring frost in Colorado ranges from April 14 in Grand Junction to June 21 in Edwards, based on NOAA 1991–2020 climate normals.

How long do broccoli take to grow?

Broccoli typically take 55–80 days from planting to harvest. Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost).

Other Crops in Colorado

When to plant broccoli in other states

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