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When to Plant Sweet Corn in Gloucester 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.

Gloucester County, New Jersey is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is November 12, giving you a growing season of approximately 221 days.

At an elevation of 735 feet, Gloucester County receives approximately 49.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94ยฐF, providing good warmth for Sweet Corn during the growing season.

Gloucester County, NJ (Zone 7a) Long season
221 days
Last Spring Frost April 5
221 growing days
First Fall Frost November 12

Gloucester County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Transplant: Mar 24 🍅 Harvest: May 26 – Jul 7
Recommended (50%) ✓ Fits season (116 days to spare)
Transplant: Apr 5 🍅 Harvest: Jun 7 – Jul 19
Safe Start (90%) ✓ Fits season (116 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 30 – Aug 11

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.

Soil Compatibility in Gloucester County

How your county's soil matches Sweet Corn's growing requirements.

Soil pH

Your soil pH (5.2โ€“6.8) overlaps with Sweet Corn's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Gloucester County is excellent for Sweet Corn โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Sweet Corn.

How to Plant Sweet Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Sweet Corn

4
successive plantings in your 221-day season

Sow every 6.9 weeks. Last sowing by Aug 14 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,085 gal / 100 sq ft

Monthly Watering Guide for Sweet Corn

Sweet Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Sweet Corn Needs Rainfall You Supplement Action
Jan โ€” 3.7" 0" โ„๏ธ Dormant
Feb โ€” 3" 0" โ„๏ธ Dormant
Mar โ€” 4.5" 0" โ„๏ธ Dormant
Apr 6.5" 4" 2.5" ๐Ÿ’ง Light watering
May 6.5" 4.8" 1.7" ๐Ÿ’ง Light watering
Jun 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
Jul 6.5" 5.3" 1.2" ๐Ÿ’ง Light watering
Aug 6.5" 4" 2.5" ๐Ÿ’ง Light watering
Sep 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
Oct 6.5" 3.9" 2.6" ๐Ÿ’ง Light watering
Nov 6.5" 4.1" 2.4" ๐Ÿ’ง Light watering
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Gloucester County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sweet Corn Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Sweet Corn needs ~1,538 GDD — county provides 4,530 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Gloucester County, NJ

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow April 12 Apr 12 โ€“ May 3
Harvest June 14 Jun 14 โ€“ Jul 26

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 โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

221 days in Gloucester County

Growing Tips for Sweet Corn in Gloucester County

Direct sow Sweet Corn outdoors after April 05 in Gloucester County when soil has warmed and frost danger has passed.

Common pests for Sweet Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Gloucester County is in Zone 7a with an average last frost of April 5. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Gloucester County, NJ?

Gloucester County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Gloucester County gardeners in Zone 7a 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 Gloucester County, NJ. Local conditions may vary. Last updated: April 2026.