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When to Plant Winter Melon in Placer County, CA

Placer County, California Zone 9b May

May to-do list for Placer County, California

A quick May briefing for Placer County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 22
Avg. first frost November 9
Soil temp (4") 72°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
Coming up in June — start thinking about
  • Starting indoors: 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.

Placer County, California is in USDA Zone 9b. The average last spring frost is April 22 and the first fall frost is November 9, giving you a growing season of approximately 201 days.

At an elevation of 651 feet, Placer County receives approximately 25.3 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Winter Melon during the growing season.

Placer County, CA (Zone 9b) Long season
201 days
Last Spring Frost April 22
201 growing days
First Fall Frost November 9
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Placer County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 3 Transplant: Apr 21 🍅 Harvest: Jul 21 – Sep 8
Recommended (50%) ✓ Fits season (54 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 29 – Sep 16
Safe Start (90%) ✓ Fits season (48 days to spare)
Start indoors: Apr 16 Transplant: Jun 4 🍅 Harvest: Sep 3 – Oct 22

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 Placer County

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

Soil pH

Your soil pH (6.6–7.2) overlaps with Winter Melon's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Placer 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 moderate (3.1%). 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
0.5″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,656 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 5.2" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 0.7" 3.6" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 4.3" 2.4" 1.9" 💧 Light watering
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Placer 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 ~1,444 GDD — county provides 2,763 GDD Excellent fit

Winter Melon Planting Timeline — Placer County, CA

Winter Melon Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest July 29 Jul 29 – Sep 16

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

201 days in Placer County

Growing Tips for Winter Melon in Placer County

Direct sow Winter Melon outdoors after April 22 in Placer County when soil has warmed and frost danger has passed.

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.

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 Placer County, CA?

Placer County is in Zone 9b with an average last frost of April 22. Plan your Winter Melon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Placer County, CA?

Placer County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 22 and first fall frost is November 9.

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Your Placer County Garden Planner — Free

A 24-page printable planner built for Placer County (Zone 9b). 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 Placer County, CA. 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.