FrostCal

When to Plant Tomatoes in Colorado

In a typical Colorado location, start seeds indoors Mar 8 – Mar 22, then transplant outdoors May 10 – May 17. Across the state, the outdoor planting window starts as early as Apr 21 in Grand Junction and as late as Jun 28 in Edwards.

Method Start indoors, then transplant
Days to maturity 60–85 days

Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed.

Tomatoes Planting Dates by City

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

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 tomatoes in Colorado?

In a typical Colorado location, start seeds indoors Mar 8 – Mar 22, then transplant outdoors May 10 – May 17. Across the state, the outdoor planting window starts as early as Apr 21 in Grand Junction and as late as Jun 28 in Edwards.

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 tomatoes take to grow?

Tomatoes typically take 60–85 days from planting to harvest. Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed.

Other Crops in Colorado

When to plant tomatoes in other states

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