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When to Plant Soybeans in Salem County, NJ

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Salem County, New Jersey is in USDA Zone 7a. 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 88ยฐF, providing good warmth for Soybeans during the growing season.

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

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 (68 days to spare)
Transplant: Mar 30 🍅 Harvest: Jun 22 – Aug 17
Recommended (50%) ✓ Fits season (69 days to spare)
Transplant: Apr 6 🍅 Harvest: Jun 29 – Aug 24
Safe Start (90%) ✓ Fits season (60 days to spare)
Transplant: Apr 28 🍅 Harvest: Jul 21 – Sep 15

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 Soybeans's growing requirements.

Soil pH

Your soil pH (4.9โ€“6.4) is more acidic than Soybeans prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Soybeans.

Organic Matter

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

How to Plant Soybeans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Soybeans

3
successive plantings in your 209-day season

Sow every 9.1 weeks. Last sowing by Jul 04 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Soybeans

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

Month Soybeans Needs Rainfall You Supplement Action
Jan โ€” 2.7" 0" โ„๏ธ Dormant
Feb โ€” 2.8" 0" โ„๏ธ Dormant
Mar โ€” 3.1" 0" โ„๏ธ Dormant
Apr 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
May 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Jun 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Jul 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Aug 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Sep 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Oct 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Nov 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Dec โ€” 3" 0" โ„๏ธ Dormant

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

Soybeans 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.

Soybeans needs ~1,600 GDD — county provides 3,344 GDD Excellent fit

Soybeans Planting Timeline โ€” Salem County, NJ

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest July 6 Jul 6 โ€“ Aug 31

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

209 days in Salem County

Growing Tips for Soybeans in Salem County

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

Common pests for Soybeans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Soybeans in Salem County, NJ?

Salem County is in Zone 7a with an average last frost of April 6. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Salem County, NJ?

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

๐ŸŒฑ

Plan Your Garden with Confidence

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