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When to Plant Corn in Salem County, NJ

Salem County, New Jersey Zone 7b May

Salem County, New Jersey gardeners: here's your May plan

Each item below is timed to Salem County, New Jersey's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 6
Avg. first frost November 1
Soil temp (4") 66°F
Watering Moderate
Pest pressure Moderate
Daylight 14.2 hrs
To set up a strong June, finish these tasks
  • First harvests: corn

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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.

Salem County, New Jersey is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 1,061 feet, Salem County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Corn during the growing season.

Salem County, NJ (Zone 7b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1
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Salem County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Transplant: Mar 30 🍅 Harvest: Jun 1 – Jul 27
Recommended (50%) ✓ Fits season (90 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 8 – Aug 3
Safe Start (90%) ✓ Fits season (81 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 30 – Aug 25

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 Salem County

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

Soil pH

Your soil pH (4.9–6.4) is more acidic than Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Salem County is excellent for Corn — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Corn.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Corn.

How to Plant Corn

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

Succession Planting Corn

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Jul 24 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 499 gal / 100 sq ft

Monthly Watering Guide for Corn

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 Corn Needs Rainfall You Supplement Action
Jan 2.7" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 3.3" 3.2" 💧 Light watering
Jun 6.5" 3.8" 2.7" 💧 Light watering
Jul 6.5" 3.8" 2.7" 💧 Light watering
Aug 6.5" 3.6" 2.9" 💧 Light watering
Sep 6.5" 3.6" 2.9" 💧 Light watering
Oct 6.5" 2.9" 3.6" 🚿 Regular watering
Nov 6.5" 2.5" 4" 🚿 Regular watering
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Salem County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

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" — every day above 50°F 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.

Corn needs ~1,280 GDD — county provides 3,344 GDD Excellent fit

Corn Planting Timeline — Salem County, NJ

Corn Planting Calendar

Activity When Date Range
Direct Sow April 13 Apr 13 – May 4
Harvest June 15 Jun 15 – Aug 10

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June Harvest
July Harvest
August Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

209 days in Salem County

Growing Tips for Corn in Salem County

Direct sow Corn outdoors after April 06 in Salem County when soil has warmed and frost danger has passed.

Common pests for 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 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Salem County, NJ?

Salem County is in Zone 7b with an average last frost of April 6. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Salem County, NJ?

Salem County, New Jersey is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is November 1.

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Your Salem County Garden Planner — Free

A 24-page printable planner built for Salem County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Salem County, NJ. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.