FrostCal

When to Plant Brussels Sprouts in Idaho

In a typical Idaho location, start seeds indoors Mar 12 – Mar 26, then transplant outdoors Apr 9 – Apr 23. Across the state, the outdoor planting window starts as early as Mar 16 in Lewiston and as late as Apr 26 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 90–110 days

Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost.

Brussels Sprouts Planting Dates by City

CityStart indoorsTransplant
BoiseMar 6 – Mar 20Apr 3 – Apr 17
MeridianMar 6 – Mar 20Apr 3 – Apr 17
NampaMar 11 – Mar 25Apr 8 – Apr 22
Idaho FallsMar 21 – Apr 4Apr 18 – May 2
PocatelloMar 14 – Mar 28Apr 11 – Apr 25
CaldwellMar 5 – Mar 19Apr 2 – Apr 16
Coeur d'AleneMar 4 – Mar 18Apr 1 – Apr 15
Twin FallsMar 12 – Mar 26Apr 9 – Apr 23
LewistonFeb 16 – Mar 2Mar 16 – Mar 30
Lewiston OrchardsFeb 16 – Mar 2Mar 16 – Mar 30
Post FallsMar 4 – Mar 18Apr 1 – Apr 15
RexburgMar 27 – Apr 10Apr 24 – May 8
MoscowFrost-free: year-round planting
EagleMar 29 – Apr 12Apr 26 – May 10
CondaFrost-free: year-round planting
KunaMar 6 – Mar 20Apr 3 – Apr 17
AmmonMar 21 – Apr 4Apr 18 – May 2
ChubbuckMar 14 – Mar 28Apr 11 – Apr 25
HaydenMar 4 – Mar 18Apr 1 – Apr 15
Mountain HomeMar 14 – Mar 28Apr 11 – Apr 25
BlackfootMar 17 – Mar 31Apr 14 – Apr 28
Garden CityMar 6 – Mar 20Apr 3 – Apr 17
JeromeMar 14 – Mar 28Apr 11 – Apr 25
BurleyMar 19 – Apr 2Apr 16 – Apr 30

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 Brussels sprouts in Idaho?

In a typical Idaho location, start seeds indoors Mar 12 – Mar 26, then transplant outdoors Apr 9 – Apr 23. Across the state, the outdoor planting window starts as early as Mar 16 in Lewiston and as late as Apr 26 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 Brussels sprouts take to grow?

Brussels Sprouts typically take 90–110 days from planting to harvest. Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost.

Other Crops in Idaho

When to plant Brussels sprouts in other states

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