Warm-Season Vegetable

When to Plant Corn (Sweet) in Delaware

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

The Short Answer

In Delaware, corn (sweet) planting dates vary by region. In Northern Delaware, your average last frost is around Apr 10 - Apr 25, while Southern Delaware sees its last frost around Apr 1 - Apr 15. Since corn (sweet) are frost-sensitive, direct sow 2 weeks after your last frost date. Sandy soils in south, clay loam in north. Generally well-drained. Slightly acidic.

Delaware Frost Dates

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

Region	Zones	Last Frost (Spring)	First Frost (Fall)
Northern Delaware	7a	Apr 10 - Apr 25	Oct 10 - Oct 25
Southern Delaware	7b	Apr 1 - Apr 15	Oct 20 - Nov 5

Corn (Sweet) Planting Schedule for Delaware

Northern Delaware (Zones 7a)

Average last frost: Apr 10 - Apr 25 · Average first frost: Oct 10 - Oct 25

Direct Sow

2 wks after frost

Southern Delaware (Zones 7b)

Average last frost: Apr 1 - Apr 15 · Average first frost: Oct 20 - Nov 5

Direct Sow

2 wks after frost

Growing Corn (Sweet) in Delaware

Corn (Sweet) in Delaware's Climate

Your climate is classic corn country. Direct sow from mid-May. Succession plant through late June for harvests from July through September. Moderate summer temperatures produce long-lasting ears without the heat stress that shortens quality in southern states. European corn borer and corn earworm are the primary pests.

Soil Considerations for Delaware

Sandy soils in south, clay loam in north. Generally well-drained. Slightly acidic. Make sure soil has warmed to at least 60°F before planting corn (sweet) outside.

Delaware Climate & Growing Season

Moderate climate with maritime influence. Good growing conditions for a wide range of vegetables. 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 Delaware: Northern Delaware (7a) has a last frost around Apr 10 - Apr 25, while Southern Delaware (7b) sees frost end around Apr 1 - Apr 15. 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 Delaware, but your exact planting dates depend on which region you're in. Northern Delaware gardeners should plan around a Apr 10 - Apr 25 last frost, while those in Southern Delaware 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