Warm-Season Vegetable

When to Plant Corn (Sweet) in Alaska

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

The Short Answer

In Alaska, corn (sweet) planting dates vary by region. In Interior Alaska, your average last frost is around May 15 - Jun 1, while Southeast Alaska sees its last frost around Apr 15 - May 5. Since corn (sweet) are frost-sensitive, direct sow 2 weeks after your last frost date. Varies widely. Interior has permafrost challenges. Raised beds essential for warming soil. Highly acidic soils common.

Alaska Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Interior Alaska 1a, 2a, 2b May 15 - Jun 1 Aug 20 - Sep 10
Southcentral Alaska 3b, 4a, 4b May 1 - May 20 Sep 10 - Sep 25
Southeast Alaska 5a, 5b, 6a Apr 15 - May 5 Sep 25 - Oct 15

Corn (Sweet) Planting Schedule for Alaska

Interior Alaska (Zones 1a, 2a, 2b)

Average last frost: May 15 - Jun 1 · Average first frost: Aug 20 - Sep 10

Direct Sow
2 wks after frost

Southcentral Alaska (Zones 3b, 4a, 4b)

Average last frost: May 1 - May 20 · Average first frost: Sep 10 - Sep 25

Direct Sow
2 wks after frost

Southeast Alaska (Zones 5a, 5b, 6a)

Average last frost: Apr 15 - May 5 · Average first frost: Sep 25 - Oct 15

Direct Sow
2 wks after frost

Growing Corn (Sweet) in Alaska

Corn (Sweet) in Alaska'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 Alaska

Varies widely. Interior has permafrost challenges. Raised beds essential for warming soil. Highly acidic soils common. Make sure soil has warmed to at least 60°F before planting corn (sweet) outside.

Alaska Climate & Growing Season

Extreme daylight variation. Summer days of 18-24 hours of sunlight accelerate growth. Very short growing season in interior. 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 Alaska: Interior Alaska (1a, 2a, 2b) has a last frost around May 15 - Jun 1, while Southeast Alaska (5a, 5b, 6a) sees frost end around Apr 15 - May 5. 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 Alaska, but your exact planting dates depend on which region you're in. Interior Alaska gardeners should plan around a May 15 - Jun 1 last frost, while those in Southeast Alaska can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.
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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