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When to Plant Corn in Union County, NJ

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.

Union County, New Jersey is in USDA Zone 7a. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.

At an elevation of 814 feet, Union County receives approximately 49.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93Β°F, providing good warmth for Corn during the growing season.

Union County, NJ (Zone 7a) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.5

Drainage

Well Drained

How Much Corn to Grow

1-2 ears
Average yield per plant
15
Plants per person
30 sq ft
Space per person

For a family of 4, plant approximately 60 corn plants in about 120 sq ft. In Union County's 228-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Corn

Corn needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Corn Needs Rainfall You Supplement Action
Jan β€” 3" 0" ❄️ Dormant
Feb β€” 3.2" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" βœ… Rainfall sufficient
Apr 4.3" 4.8" 0" βœ… Rainfall sufficient
May 4.3" 4.2" 0.1" πŸ’§ Light watering
Jun 4.3" 4.3" 0" βœ… Rainfall sufficient
Jul 4.3" 5.4" 0" βœ… Rainfall sufficient
Aug 4.3" 4.4" 0" βœ… Rainfall sufficient
Sep 4.3" 4.1" 0.2" πŸ’§ Light watering
Oct 4.3" 3.9" 0.4" πŸ’§ Light watering
Nov 4.3" 3.7" 0.6" πŸ’§ Light watering
Dec β€” 4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Union County). Supplement amounts are based on average rainfall β€” actual needs vary with temperature, soil, and mulching.

Corn Planting Timeline β€” Union County, NJ

Corn Planting Calendar

Activity When Date Range
Direct Sow April 5 Apr 5 – Apr 26
Harvest June 7 Jun 7 – Aug 2

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

Month-by-Month Timeline

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

Growing Conditions

β˜€οΈ Sun

Full Sun (6-8+ hours)

πŸ’§ Water

Moderate β€” regular watering

πŸ“… Days to Maturity

60–100 days

πŸ§ͺ Soil pH

Needs 6–7 Β· Your soil: N/A

πŸ—ΊοΈ USDA Zone

Zone 7a

πŸ“† Growing Season

228 days in Union County

Growing Tips for Union 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Union County, NJ?

Union County is in Zone 7a with an average last frost of March 29. Plan your Corn planting based on this frost date β€” see the calendar above for exact timing.

What planting zone is Union County, NJ?

Union County, New Jersey is in USDA Hardiness Zone 7a. The average last spring frost is March 29 and first fall frost is November 12.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner β€” designed to help Union 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 Union County, NJ. Local conditions may vary. Last updated: April 2026.