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When to Plant Watermelon in Atlantic County, NJ

Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.

Atlantic 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 232 feet, Atlantic County receives approximately 49.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Watermelon during the growing season.

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

Atlantic County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Start indoors: Feb 24 Transplant: Apr 7 🍅 Harvest: Jun 16 – Aug 4
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Mar 8 Transplant: Apr 19 🍅 Harvest: Jun 28 – Aug 16
Safe Start (90%) ✓ Fits season (88 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 21 – Sep 8

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 Atlantic County

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

Soil pH

Your soil pH (5.2โ€“6.2) is more acidic than Watermelon prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Watermelon.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Watermelon.

How to Plant Watermelon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Watermelon

3
successive plantings in your 221-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 215 gal / 100 sq ft

Monthly Watering Guide for Watermelon

Watermelon 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 Watermelon Needs Rainfall You Supplement Action
Jan โ€” 4" 0" โ„๏ธ Dormant
Feb โ€” 3.6" 0" โ„๏ธ Dormant
Mar โ€” 4.2" 0" โ„๏ธ Dormant
Apr 6.5" 4.6" 1.9" ๐Ÿ’ง Light watering
May 6.5" 4.6" 1.9" ๐Ÿ’ง Light watering
Jun 6.5" 4" 2.5" ๐Ÿ’ง Light watering
Jul 6.5" 5.3" 1.2" ๐Ÿ’ง Light watering
Aug 6.5" 3.9" 2.6" ๐Ÿ’ง Light watering
Sep 6.5" 4.6" 1.9" ๐Ÿ’ง Light watering
Oct 6.5" 3.6" 2.9" ๐Ÿ’ง Light watering
Nov 6.5" 3.2" 3.3" ๐Ÿšฟ Regular watering
Dec โ€” 3.9" 0" โ„๏ธ Dormant

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

Watermelon 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.

Watermelon needs ~1,551 GDD — county provides 4,033 GDD Excellent fit

Watermelon Planting Timeline โ€” Atlantic County, NJ

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 โ€“ Mar 22
Transplant Outdoors April 19 Apr 19 โ€“ May 3
Direct Sow April 12 Apr 12 โ€“ May 3
Harvest June 28 Jun 28 โ€“ Aug 16

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
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

1.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

221 days in Atlantic County

Growing Tips for Watermelon in Atlantic County

Direct sow Watermelon outdoors after April 05 in Atlantic County when soil has warmed and frost danger has passed.

Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.

Recommended Watermelon Varieties for Atlantic County

Full-size melons that thrive with your long season

Crimson Sweet (85d) Charleston Gray (85d) Moon and Stars (95d)

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watermelon in Atlantic County, NJ?

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

What planting zone is Atlantic County, NJ?

Atlantic 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 Atlantic 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 Atlantic County, NJ. Local conditions may vary. Last updated: April 2026.