FrostCal

When to Plant Basil in Colorado

In a typical Colorado location, start seeds indoors Mar 22 – Mar 29, 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 50–70 days

Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm.

Basil Planting Dates by City

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

In a typical Colorado location, start seeds indoors Mar 22 – Mar 29, 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 basil take to grow?

Basil typically take 50–70 days from planting to harvest. Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm.

Other Crops in Colorado

When to plant basil in other states

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