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When to Plant Corn in Onslow County, NC

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Onslow County, North Carolina is in USDA Zone 8a. The average last spring frost is March 21 and the first fall frost is November 18, giving you a growing season of approximately 242 days.

At an elevation of 541 feet, Onslow County receives approximately 46.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90ยฐF, providing good warmth for Corn during the growing season. Clay soil retains moisture well for Corn, but amend with compost to improve drainage and prevent root rot.

Onslow County, NC (Zone 8a) Long season
242 days
Last Spring Frost March 21
242 growing days
First Fall Frost November 18

Onslow County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (126 days to spare)
Transplant: Mar 11 🍅 Harvest: May 13 – Jul 8
Recommended (50%) ✓ Fits season (123 days to spare)
Transplant: Mar 21 🍅 Harvest: May 23 – Jul 18
Safe Start (90%) ✓ Fits season (119 days to spare)
Transplant: Apr 8 🍅 Harvest: Jun 10 – Aug 5

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 404 gal / 100 sq ft
Corn needs ~1,400 GDD — county provides 4,235 GDD Excellent fit

Corn Planting Timeline โ€” Onslow County, NC

Corn Planting Calendar

Activity When Date Range
Direct Sow March 28 Mar 28 โ€“ Apr 18
Harvest May 30 May 30 โ€“ Jul 25

Plant 1" deep ยท 12" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April Direct Sow
May Harvest
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 8a

Growing Season

242 days

Growing Tips for Onslow County

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Level Up Your Garden

Frequently Asked Questions

When should I plant Corn in Onslow County, NC?

Onslow County is in Zone 8a with an average last frost of March 21. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Onslow County, NC?

Onslow County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 21 and first fall frost is November 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Onslow County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Onslow County, NC. Local conditions may vary. Last updated: April 2026.