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When to Plant Winter Melon in Grant County, OR

Grant County, Oregon Zone 6b May

What to do in May

Your garden in Grant County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost June 6
Avg. first frost September 10
Soil temp (4") 51°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
To set up a strong June, finish these tasks
  • Transplants going out: winter melon
  • Direct-sowing: 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.

Grant County, Oregon is in USDA Zone 6b. The average last spring frost is June 6 and the first fall frost is September 10, giving you a growing season of approximately 96 days.

At an elevation of 2,838 feet, Grant County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Winter Melon to ensure they mature before fall.

Grant County, OR (Zone 6b) Very short season
96 days
Last Spring Frost June 6
96 growing days
First Fall Frost September 10
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Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 25 Transplant: Jun 3 🍅 Harvest: Sep 2 – Oct 21
Recommended (50%) ✗ May not fit
Start indoors: Apr 11 Transplant: Jun 20 🍅 Harvest: Sep 19 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: May 1 Transplant: Jul 10 🍅 Harvest: Oct 9 – Nov 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 Grant County

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

Soil pH

Your soil pH (5.4–6.4) is more acidic than Winter Melon prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Winter Melon.

Organic Matter

Organic matter is excellent (4.8%) — Winter Melon will thrive.

How to Plant Winter Melon

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 266 gal / 100 sq ft

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 3.2" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 1.3" 0" ❄️ Dormant
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 3.1" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Grant 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 1,176 GDD Tight fit

Winter Melon Planting Timeline — Grant County, OR

Winter Melon Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 – Apr 25
Transplant Outdoors June 20 Jun 20 – Jul 4
Direct Sow June 13 Jun 13 – Jul 4
Harvest September 19 Sep 19 – Nov 7

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6b

📆 Growing Season

96 days in Grant County

Growing Tips for Winter Melon in Grant County

Direct sow Winter Melon outdoors after June 06 in Grant County when soil has warmed and frost danger has passed.

Your 96.0-day growing season in Grant 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.

Grant County receives only 23" 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 Grant County, OR?

Grant County is in Zone 6b with an average last frost of June 6. Plan your Winter Melon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, OR?

Grant County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 6 and first fall frost is September 10.

🌱

Your Grant County Garden Planner — Free

A 24-page printable planner built for Grant County (Zone 6b). 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 Grant County, OR. 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.