Blog

When to Plant Watermelon in Eddy County, ND

Eddy County, North Dakota Zone 4a May

Eddy County, North Dakota gardeners: here's your May plan

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 13
Avg. first frost September 27
Soil temp (4") 51°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Scatter watermelon into prepared beds

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Get ahead of June
  • Transplants going out: watermelon
  • Starting indoors: watermelon

Instant PDF download. No spam, unsubscribe any time.

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.

Eddy County, North Dakota is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 27, giving you a growing season of approximately 137 days.

At an elevation of 864 feet, Eddy County receives approximately 29.3 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Watermelon to ensure they mature before fall.

Eddy County, ND (Zone 4a) Short season
137 days
Last Spring Frost May 13
137 growing days
First Fall Frost September 27
Share this guide:

Eddy County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 26 Transplant: May 28 🍅 Harvest: Aug 6 – Sep 24
Recommended (50%) ✗ May not fit
Start indoors: Apr 1 Transplant: Jun 3 🍅 Harvest: Aug 12 – Sep 30
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: Apr 13 Transplant: Jun 15 🍅 Harvest: Aug 24 – Oct 12

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 Eddy County

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

Soil pH

Your soil pH (6.4–7.4) is within Watermelon's preferred range (6.0–7.5).

Soil Texture

The loam soil in Eddy County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Watermelon.

How to Plant Watermelon

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

Succession Planting Watermelon

2
successive plantings in your 137-day season

Sow every 8 weeks. Last sowing by Jun 19 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 880 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.7" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 6.5" 4.8" 1.7" 💧 Light watering
Jun 6.5" 4.3" 2.2" 💧 Light watering
Jul 6.5" 3.5" 3" 💧 Light watering
Aug 6.5" 3.7" 2.8" 💧 Light watering
Sep 6.5" 2.4" 4.1" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Eddy County). Supplement amounts are based on average rainfall — 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" — 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.

Watermelon needs ~722 GDD — county provides 1,164 GDD Excellent fit

Watermelon Planting Timeline — Eddy County, ND

Watermelon Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors June 3 Jun 3 – Jun 17
Direct Sow May 27 May 27 – Jun 17
Harvest August 12 Aug 12 – Sep 30

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Direct Sow
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

137 days in Eddy County

Growing Tips for Watermelon in Eddy County

Direct sow Watermelon outdoors after May 13 in Eddy 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 Eddy County

Compact, early melons for shorter seasons

Sugar Baby (75d) Blacktail Mountain (70d) Golden Midget (70d)

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 Eddy County, ND?

Eddy County is in Zone 4a with an average last frost of May 13. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Eddy County, ND?

Eddy County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 27.

🌱

Your Eddy County Garden Planner — Free

A 24-page printable planner built for Eddy County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Eddy County, ND. 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.