FrostCal

When to Plant Marigolds in Idaho

In a typical Idaho location, start seeds indoors Mar 19 – Apr 2, then transplant outdoors May 7 – May 14. Across the state, the outdoor planting window starts as early as Apr 13 in Lewiston and as late as May 24 in Eagle. 2 cities in Idaho are essentially frost-free and can plant on a year-round schedule.

Method Start indoors, then transplant
Days to maturity 45–60 days

Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed.

Marigolds Planting Dates by City

CityStart indoorsTransplant
BoiseMar 13 – Mar 27May 1 – May 8
MeridianMar 13 – Mar 27May 1 – May 8
NampaMar 18 – Apr 1May 6 – May 13
Idaho FallsMar 28 – Apr 11May 16 – May 23
PocatelloMar 21 – Apr 4May 9 – May 16
CaldwellMar 12 – Mar 26Apr 30 – May 7
Coeur d'AleneMar 11 – Mar 25Apr 29 – May 6
Twin FallsMar 19 – Apr 2May 7 – May 14
LewistonFeb 23 – Mar 9Apr 13 – Apr 20
Lewiston OrchardsFeb 23 – Mar 9Apr 13 – Apr 20
Post FallsMar 11 – Mar 25Apr 29 – May 6
RexburgApr 3 – Apr 17May 22 – May 29
MoscowFrost-free: year-round planting
EagleApr 5 – Apr 19May 24 – May 31
CondaFrost-free: year-round planting
KunaMar 13 – Mar 27May 1 – May 8
AmmonMar 28 – Apr 11May 16 – May 23
ChubbuckMar 21 – Apr 4May 9 – May 16
HaydenMar 11 – Mar 25Apr 29 – May 6
Mountain HomeMar 21 – Apr 4May 9 – May 16
BlackfootMar 24 – Apr 7May 12 – May 19
Garden CityMar 13 – Mar 27May 1 – May 8
JeromeMar 21 – Apr 4May 9 – May 16
BurleyMar 26 – Apr 9May 14 – May 21

Showing the 24 most populous of 24 Idaho cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Idaho cities.

Frequently Asked Questions

When should I plant marigolds in Idaho?

In a typical Idaho location, start seeds indoors Mar 19 – Apr 2, then transplant outdoors May 7 – May 14. Across the state, the outdoor planting window starts as early as Apr 13 in Lewiston and as late as May 24 in Eagle. 2 cities in Idaho are essentially frost-free and can plant on a year-round schedule.

When is the last frost in Idaho?

The average last spring frost in Idaho ranges from April 6 in Lewiston to May 17 in Eagle, based on NOAA 1991–2020 climate normals.

How long do marigolds take to grow?

Marigolds typically take 45–60 days from planting to harvest. Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed.

Other Crops in Idaho

When to plant marigolds in other states

Related Guides