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When to Plant Winter Melon in Grant County, WA

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, Washington is in USDA Zone 7a. The average last spring frost is April 29 and the first fall frost is October 10, giving you a growing season of approximately 164 days.

At an elevation of 3,122 feet, Grant County receives approximately 17.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Winter Melon during the growing season. With low rainfall, drip irrigation is essential for growing Winter Melon successfully. Mulch heavily to conserve soil moisture.

Grant County, WA (Zone 7a) Moderate season
164 days
Last Spring Frost April 29
164 growing days
First Fall Frost October 10

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

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 2.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 0.7" 3.6" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.6" 3.7" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

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

Winter Melon Planting Timeline — Grant County, WA

Winter Melon Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest August 12 Aug 12 – Sep 30

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

164 days in Grant County

Growing Tips for Grant County

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, WA?

Grant County is in Zone 7a with an average last frost of April 29. Plan your Winter Melon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, WA?

Grant County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 29 and first fall frost is October 10.

🌱

Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant County (Zone 7a). 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, WA. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.