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When to Plant Watermelon in Butler County, MO

Butler County, Missouri Zone 7b May

Top priorities for Butler County, Missouri gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Butler County, Missouri.

Avg. last frost March 27
Avg. first frost November 2
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14 hrs
Get ahead of June
  • 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.

Butler County, Missouri is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 2, giving you a growing season of approximately 220 days.

At an elevation of 703 feet, Butler County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Watermelon during the growing season.

Butler County, MO (Zone 7b) Long season
220 days
Last Spring Frost March 27
220 growing days
First Fall Frost November 2

Butler County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Feb 19 Transplant: Apr 2 🍅 Harvest: Jun 11 – Jul 30
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🍅 Harvest: Jun 19 – Aug 7
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jul 10 – Aug 28

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 Butler County

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

Soil pH

Your soil pH (5.5–6.6) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Butler 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 220-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
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,558 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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 6.5" 2.5" 4" 🚿 Regular watering
Apr 6.5" 3.7" 2.8" 💧 Light watering
May 6.5" 4.8" 1.7" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 3.6" 2.9" 💧 Light watering
Oct 6.5" 3" 3.5" 🚿 Regular watering
Nov 6.5" 2.3" 4.2" 🚿 Regular watering
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Butler 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 ~1,551 GDD — county provides 4,015 GDD Excellent fit

Watermelon Planting Timeline — Butler County, MO

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow April 3 Apr 3 – Apr 24
Harvest June 19 Jun 19 – Aug 7

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

Month-by-Month Timeline

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

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

220 days in Butler County

Growing Tips for Watermelon in Butler County

Direct sow Watermelon outdoors after March 27 in Butler 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 Butler 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 Butler County, MO?

Butler County is in Zone 7b with an average last frost of March 27. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Butler County, MO?

Butler County, Missouri is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 2.

🌱

Your Butler County Garden Planner — Free

A 24-page printable planner built for Butler 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 Butler 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.