Blog

When to Plant Sweet Corn in Warren County, NJ

Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.

Warren County, New Jersey is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.

At an elevation of 369 feet, Warren County receives approximately 48.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Sweet Corn during the growing season.

Warren County, NJ (Zone 6a) Moderate season
194 days
Last Spring Frost April 16
194 growing days
First Fall Frost October 27

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 8 – Jul 20
Recommended (50%) ✓ Fits season (89 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 18 – Jul 30
Safe Start (90%) ✓ Fits season (85 days to spare)
Transplant: May 9 🍅 Harvest: Jul 11 – Aug 22

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sweet Corn needs ~1,088 GDD — county provides 2,813 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Warren County, NJ

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 23 Apr 23 โ€“ May 14
Harvest June 25 Jun 25 โ€“ Aug 6

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Direct Sow
June Harvest
July Harvest
August Harvest
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€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

194 days

Growing Tips for Warren County

Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Sweet Corn in Warren County, NJ?

Warren County is in Zone 6a with an average last frost of April 16. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Warren County, NJ?

Warren County, New Jersey is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Warren County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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