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When to Plant Winter Melon in Park County, WY

Park County, Wyoming Zone 5a May

May in the garden — Park County, Wyoming

Here's what deserves your attention in Park County, Wyoming this month. Everything below is tailored to Zone 5a and timed around your local frost dates.

Avg. last frost May 21
Avg. first frost September 22
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Plant winter melon from seed, right in the garden

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

Coming up in June — start thinking about
  • Transplants going out: winter melon

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Winter melon (wax gourd) is a large Asian squash with a waxy white coating that allows long storage. The mild flesh is used in soups and stir-fries.

Park County, Wyoming is in USDA Zone 5a. The average last spring frost is May 21 and the first fall frost is September 22, giving you a growing season of approximately 124 days.

At an elevation of 6,993 feet, Park County receives approximately 16.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Winter Melon to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Winter Melon successfully. Mulch heavily to conserve soil moisture.

Park County, WY (Zone 5a) Short season
124 days
Last Spring Frost May 21
124 growing days
First Fall Frost September 22

Park County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 15 Transplant: May 24 🍅 Harvest: Aug 23 – Oct 11
Recommended (50%) ✗ May not fit
Start indoors: Mar 26 Transplant: Jun 4 🍅 Harvest: Sep 3 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: May 3 Transplant: Jul 12 🍅 Harvest: Oct 11 – Nov 29

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 Park County

How your county's soil matches Winter Melon's growing requirements.

Soil pH

Your soil pH (6.8–8.2) is more alkaline than Winter Melon prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Park County is excellent for Winter Melon — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Winter Melon.

How to Plant Winter Melon

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 575 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Winter Melon

Winter Melon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Winter Melon Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Park County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Winter Melon 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.

Winter Melon needs ~1,286 GDD — county provides 1,519 GDD Good fit

Winter Melon Planting Timeline — Park County, WY

Winter Melon Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors June 4 Jun 4 – Jun 18
Direct Sow May 28 May 28 – Jun 18
Harvest September 3 Sep 3 – Oct 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

124 days in Park County

Growing Tips for Winter Melon in Park County

Direct sow Winter Melon outdoors after May 21 in Park County when soil has warmed and frost danger has passed.

Your 124.0-day growing season in Park County is tight for Winter Melon (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Winter Melon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

Park County receives only 17" of rain annually. Winter Melon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 3-4 weeks early. Provide ample space for sprawling vines. Harvest when the waxy coating develops on the rind. Fruits can weigh 15-30 pounds.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Winter Melon in Park County, WY?

Park County is in Zone 5a with an average last frost of May 21. Plan your Winter Melon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Park County, WY?

Park County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 21 and first fall frost is September 22.

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Your Park County Garden Planner — Free

A 24-page printable planner built for Park 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 Park 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.