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When to Plant Watermelon in Converse County, WY

Converse County, Wyoming Zone 5a May

May in Converse County, Wyoming — your action list

We've pulled the most time-sensitive tasks for Converse County, Wyoming this May and put them front and centre. Tackle them in order.

Avg. last frost June 4
Avg. first frost September 18
Soil temp (4") 37°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
Looking ahead to June
  • Transplants going out: watermelon
  • Direct-sowing: 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.

Converse County, Wyoming is in USDA Zone 5a. The average last spring frost is June 4 and the first fall frost is September 18, giving you a growing season of approximately 106 days.

At an elevation of 6,089 feet, Converse County receives approximately 16.3 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Watermelon to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Watermelon successfully. Mulch heavily to conserve soil moisture.

Converse County, WY (Zone 5a) Short season
106 days
Last Spring Frost June 4
106 growing days
First Fall Frost September 18

Converse County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 16 Transplant: Jun 4 🍅 Harvest: Aug 13 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: Apr 30 Transplant: Jun 18 🍅 Harvest: Aug 27 – Oct 15
Safe Start (90%) ✗ May not fit
Start indoors: May 13 Transplant: Jul 1 🍅 Harvest: Sep 9 – Oct 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 Converse County

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

Soil pH

Your soil pH (6.6–8.3) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Watermelon.

How to Plant Watermelon

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

How Much Watermelon to Grow

15-20 lbs
Average yield per plant
1
Plants per person
8.8 sq ft
Space per person

For a family of 4, plant approximately 4 watermelon plants in about 35 sq ft. In Converse County's 106-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 967 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.2" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 2" 0" ❄️ Dormant
Jun 6.5" 1.2" 5.3" 🚿 Regular watering
Jul 6.5" 1.5" 5" 🚿 Regular watering
Aug 6.5" 1.5" 5" 🚿 Regular watering
Sep 6.5" 1.3" 5.2" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Converse 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 ~914 GDD — county provides 1,139 GDD Good fit

Watermelon Planting Timeline — Converse County, WY

Watermelon Planting Calendar

Activity When Date Range
Start Indoors April 30 Apr 30 – May 14
Transplant Outdoors June 18 Jun 18 – Jul 2
Direct Sow June 11 Jun 11 – Jul 2
Harvest August 27 Aug 27 – Oct 15

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors
June Transplant Outdoors Direct Sow
July Transplant Outdoors Direct Sow
August Harvest
September Harvest
October Harvest
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 5a

📆 Growing Season

106 days in Converse County

Growing Tips for Watermelon in Converse County

Direct sow Watermelon outdoors after June 04 in Converse County when soil has warmed and frost danger has passed.

Your 106.0-day growing season in Converse County is tight for Watermelon (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

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.

Converse County receives only 16" of rain annually. Watermelon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Converse 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 Converse County, WY?

Converse County is in Zone 5a with an average last frost of June 4. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Converse County, WY?

Converse County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is June 4 and first fall frost is September 18.

🌱

Your Converse County Garden Planner — Free

A 24-page printable planner built for Converse County (Zone 5a). 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 Converse County, WY. 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.