Root Vegetable

When to Plant Radishes in Montana

The fastest vegetable in the garden — some varieties are ready in just 25 days. Perfect for impatient gardeners and kids.

The Short Answer

In Montana, soil conditions are an important factor for radishes. Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges. Direct sow 4 weeks before your last frost date. Radishes can also be planted in fall, 6 weeks before your first frost.

Montana Frost Dates

Your planting dates depend on which part of Montana you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Western Montana 4b, 5a, 5b May 10 - May 30 Sep 10 - Sep 30
Central Montana 3b, 4a, 4b May 15 - Jun 5 Sep 5 - Sep 20
Eastern Montana 3a, 3b, 4a May 10 - Jun 1 Sep 10 - Sep 25

Radishes Planting Schedule for Montana

Western Montana (Zones 4b, 5a, 5b)

Average last frost: May 10 - May 30 · Average first frost: Sep 10 - Sep 30

Direct Sow
4 wks before frost
Fall Planting
6 wks before first frost

Central Montana (Zones 3b, 4a, 4b)

Average last frost: May 15 - Jun 5 · Average first frost: Sep 5 - Sep 20

Direct Sow
4 wks before frost
Fall Planting
6 wks before first frost

Eastern Montana (Zones 3a, 3b, 4a)

Average last frost: May 10 - Jun 1 · Average first frost: Sep 10 - Sep 25

Direct Sow
4 wks before frost
Fall Planting
6 wks before first frost

Growing Radishes in Montana

Radishes in Montana's Climate

Radishes are perfect for cold-climate gardens — they're the fastest crop from seed to harvest (as few as 22 days) and tolerate frost. Direct sow as soon as soil thaws. Your cool, long spring means radishes grow for weeks without the bolting pressure that ends the season rapidly in warm zones. Fall radishes from an August sowing are equally productive.

Soil Considerations for Montana

Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges. Loose, well-drained soil is especially important for radishes since the edible portion grows underground. If your soil is heavy clay, consider raised beds.

Montana Climate & Growing Season

Short, intense growing season. Low humidity. Wide day-night temperature swings. Wind protection valuable. Radishes can handle frost well, which is an advantage in Montana's climate. You can push planting dates earlier in spring and extend into fall.

Growing season length varies across Montana: Western Montana (4b, 5a, 5b) has a last frost around May 10 - May 30, while Eastern Montana (3a, 3b, 4a) sees frost end around May 10 - Jun 1. This difference matters for radishes — but radishes handle frost well, so the timing difference is less critical.

Growing Tips

Don't let them stay in the ground too long — they get pithy and hot. Succession plant every 2 weeks for continuous harvest.

Companion Planting

Plant radishes alongside these companions for better growth:

Peas Lettuce Carrots Spinach

The Bottom Line

Radishes can be grown successfully across Montana, but your exact planting dates depend on which region you're in. Western Montana gardeners should plan around a May 10 - May 30 last frost, while those in Eastern Montana can typically plant later. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Radishes Growing Guide National planting guide with all states Montana Planting Calendar All plants for Montana Radishes in Alabama Alabama planting dates Radishes in Alaska Alaska planting dates Radishes in Arizona Arizona planting dates Radishes in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

Ready to Start Planting?

Enter your zip code and pick your plant. We'll tell you exactly when to plant, start seeds, and harvest — based on where you live.

Find Your Planting Dates