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When to Plant Watermelon in New Madrid County, MO

New Madrid County, Missouri Zone 7b May

Your May game plan for New Madrid County, Missouri

Your New Madrid County, Missouri garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 30
Avg. first frost November 2
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 14 hrs
June will be here before you know it — start on
  • First harvests: watermelon

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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.

New Madrid County, Missouri is in USDA Zone 7b. The average last spring frost is March 30 and the first fall frost is November 2, giving you a growing season of approximately 217 days.

At an elevation of 881 feet, New Madrid County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Watermelon during the growing season.

New Madrid County, MO (Zone 7b) Long season
217 days
Last Spring Frost March 30
217 growing days
First Fall Frost November 2
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New Madrid County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Feb 23 Transplant: Apr 6 🍅 Harvest: Jun 15 – Aug 3
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Mar 2 Transplant: Apr 13 🍅 Harvest: Jun 22 – Aug 10
Safe Start (90%) ✓ Fits season (88 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: Jul 9 – Aug 27

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 New Madrid County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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 217-day season

Sow every 8 weeks. Last sowing by Jul 25 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,424 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 1.8" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 6.5" 2.8" 3.7" 🚿 Regular watering
Apr 6.5" 4.2" 2.3" 💧 Light watering
May 6.5" 4.4" 2.1" 💧 Light watering
Jun 6.5" 4.9" 1.6" 💧 Light watering
Jul 6.5" 4.6" 1.9" 💧 Light watering
Aug 6.5" 4.4" 2.1" 💧 Light watering
Sep 6.5" 3.4" 3.1" 💧 Light watering
Oct 6.5" 2.8" 3.7" 🚿 Regular watering
Nov 6.5" 2.6" 3.9" 🚿 Regular watering
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in New Madrid 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 ~1,360 GDD — county provides 3,472 GDD Excellent fit

Watermelon Planting Timeline — New Madrid County, MO

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow April 6 Apr 6 – Apr 27
Harvest June 22 Jun 22 – Aug 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May
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 · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

217 days in New Madrid County

Growing Tips for Watermelon in New Madrid County

Direct sow Watermelon outdoors after March 30 in New Madrid 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.

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 New Madrid County, MO?

New Madrid County is in Zone 7b with an average last frost of March 30. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is New Madrid County, MO?

New Madrid County, Missouri is in USDA Hardiness Zone 7b. The average last spring frost is March 30 and first fall frost is November 2.

🌱

Your New Madrid County Garden Planner — Free

A 24-page printable planner built for New Madrid 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 New Madrid County, MO. 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.