Warm-Season Vegetable

When to Plant Corn (Sweet) in Montana

Nothing says summer like fresh sweet corn. Plant in blocks (not rows) for proper pollination.

The Short Answer

In Montana, corn (sweet) planting dates vary by region. In Western Montana, your average last frost is around May 10 - May 30, while Eastern Montana sees its last frost around May 10 - Jun 1. Since corn (sweet) are frost-sensitive, direct sow 2 weeks after your last frost date. Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges.

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

Corn (Sweet) 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
2 wks after frost

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

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

Direct Sow
2 wks after frost

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

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

Direct Sow
2 wks after frost

Growing Corn (Sweet) in Montana

Corn (Sweet) in Montana's Climate

Sweet corn needs warm soil and warm nights but matures quickly enough for most cold-climate gardens. Direct sow when soil reaches 60°F — typically late May. Choose early varieties (60-65 days) for the shortest seasons. Plant in blocks of at least 4×4 for wind pollination. Raccoons are the universal corn nemesis — electric fencing is the only reliable deterrent.

Soil Considerations for Montana

Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges. Make sure soil has warmed to at least 60°F before planting corn (sweet) outside.

Montana Climate & Growing Season

Short, intense growing season. Low humidity. Wide day-night temperature swings. Wind protection valuable. Corn (Sweet) cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.

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 corn (sweet) — transplant timing shifts by several weeks across the state.

Growing Tips

Plant in blocks of at least 4x4 for wind pollination. Corn is a heavy feeder — amend soil with compost before planting.

Companion Planting

Plant corn (sweet) alongside these companions for better growth:

Beans Squash Melons

Keep corn (sweet) away from:

Tomatoes

The Bottom Line

Corn (Sweet) 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

Corn (Sweet) Growing Guide National planting guide with all states Montana Planting Calendar All plants for Montana Corn (Sweet) in Alabama Alabama planting dates Corn (Sweet) in Alaska Alaska planting dates Corn (Sweet) in Arizona Arizona planting dates Corn (Sweet) 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

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