FrostCal

When to Plant Radishes in Idaho

In a typical Idaho location, sow outdoors Mar 26 – Apr 9. Across the state, the outdoor planting window starts as early as Mar 2 in Lewiston and as late as Apr 12 in Eagle. For a fall crop, plant around Sep 2 – Sep 16. 2 cities in Idaho are essentially frost-free and can plant on a year-round schedule.

Method Direct sow
Days to maturity 22–30 days

Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked.

Radishes Planting Dates by City

CityDirect sowFall planting
BoiseMar 20 – Apr 3Sep 9 – Sep 23
MeridianMar 20 – Apr 3Sep 9 – Sep 23
NampaMar 25 – Apr 8Sep 1 – Sep 15
Idaho FallsApr 4 – Apr 18Aug 20 – Sep 3
PocatelloMar 28 – Apr 11Aug 30 – Sep 13
CaldwellMar 19 – Apr 2Sep 6 – Sep 20
Coeur d'AleneMar 18 – Apr 1Sep 6 – Sep 20
Twin FallsMar 26 – Apr 9Aug 28 – Sep 11
LewistonMar 2 – Mar 16Sep 14 – Sep 28
Lewiston OrchardsMar 2 – Mar 16Sep 14 – Sep 28
Post FallsMar 18 – Apr 1Sep 6 – Sep 20
RexburgApr 10 – Apr 24Aug 12 – Aug 26
MoscowFrost-free: year-round planting
EagleApr 12 – Apr 26Aug 31 – Sep 14
CondaFrost-free: year-round planting
KunaMar 20 – Apr 3Sep 9 – Sep 23
AmmonApr 4 – Apr 18Aug 20 – Sep 3
ChubbuckMar 28 – Apr 11Aug 30 – Sep 13
HaydenMar 18 – Apr 1Sep 6 – Sep 20
Mountain HomeMar 28 – Apr 11Aug 27 – Sep 10
BlackfootMar 31 – Apr 14Aug 22 – Sep 5
Garden CityMar 20 – Apr 3Sep 9 – Sep 23
JeromeMar 28 – Apr 11Sep 2 – Sep 16
BurleyApr 2 – Apr 16Aug 23 – Sep 6

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 radishes in Idaho?

In a typical Idaho location, sow outdoors Mar 26 – Apr 9. Across the state, the outdoor planting window starts as early as Mar 2 in Lewiston and as late as Apr 12 in Eagle. For a fall crop, plant around Sep 2 – Sep 16. 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 radishes take to grow?

Radishes typically take 22–30 days from planting to harvest. Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked.

Other Crops in Idaho

When to plant radishes in other states

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