When to Plant Corn (Sweet) in Wisconsin
Nothing says summer like fresh sweet corn. Plant in blocks (not rows) for proper pollination.
The Short Answer
Wisconsin Frost Dates
Your planting dates depend on which part of Wisconsin you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Wisconsin | 3b, 4a | May 15 - Jun 1 | Sep 10 - Sep 25 |
| Central Wisconsin | 4a, 4b | May 5 - May 20 | Sep 20 - Oct 5 |
| Southern Wisconsin | 4b, 5a, 5b | Apr 25 - May 10 | Oct 1 - Oct 15 |
Corn (Sweet) Planting Schedule for Wisconsin
Northern Wisconsin (Zones 3b, 4a)
Average last frost: May 15 - Jun 1 · Average first frost: Sep 10 - Sep 25
Central Wisconsin (Zones 4a, 4b)
Average last frost: May 5 - May 20 · Average first frost: Sep 20 - Oct 5
Southern Wisconsin (Zones 4b, 5a, 5b)
Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15
Growing Corn (Sweet) in Wisconsin
Corn (Sweet) in Wisconsin'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 Wisconsin
Rich agricultural soils in southern half. Sandy soils in central plain. Heavy clay in some lake regions. Generally fertile. Make sure soil has warmed to at least 60°F before planting corn (sweet) outside.
Wisconsin Climate & Growing Season
Cold winters. Warm summers. Lake Michigan moderates eastern climate. Good growing season in south. Short season in north. 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 Wisconsin: Northern Wisconsin (3b, 4a) has a last frost around May 15 - Jun 1, while Southern Wisconsin (4b, 5a, 5b) sees frost end around Apr 25 - May 10. 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:
Keep corn (sweet) away from:
The Bottom Line
Last reviewed: March 29, 2026