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When to Plant Watermelon in Converse County, WY

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 4b. 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 81ยฐF, 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 4b) 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 9 Transplant: Jun 11 🍅 Harvest: Aug 20 – Oct 8
Recommended (50%) ✗ May not fit
Start indoors: Apr 23 Transplant: Jun 25 🍅 Harvest: Sep 3 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: May 6 Transplant: Jul 8 🍅 Harvest: Sep 16 – Nov 4

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 (6.6โ€“8.3) overlaps with Watermelon's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Converse County is excellent for Watermelon โ€” 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

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 โ€” consider drought-tolerant varieties and mulching

Watermelon needs ~914 GDD — county provides 1,139 GDD Good fit

Watermelon Planting Timeline โ€” Converse County, WY

Watermelon Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 โ€“ May 7
Transplant Outdoors June 25 Jun 25 โ€“ Jul 9
Direct Sow June 18 Jun 18 โ€“ Jul 9
Harvest September 3 Sep 3 โ€“ Oct 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† 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 โ€” 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Watermelon in Converse County, WY?

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

What planting zone is Converse County, WY?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Converse County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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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: April 2026.