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When to Plant Kabocha in Plumas County, CA

Plumas County, California Zone 7b May

May to-do list for Plumas County, California

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

Avg. last frost May 20
Avg. first frost October 8
Soil temp (4") 64°F
Watering Critical
Pest pressure Low
Daylight 14.2 hrs
  1. Sow kabocha where they'll grow

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

A few tasks this May that'll pay off in June
  • Transplants going out: kabocha
  • Starting indoors: kabocha

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Kabocha is a Japanese winter squash with an exceptionally sweet, dense, chestnut-like flesh and dark green skin. It is a favorite in Asian cuisine for its rich, dry texture.

Plumas County, California is in USDA Zone 7b. The average last spring frost is May 20 and the first fall frost is October 8, giving you a growing season of approximately 141 days.

At an elevation of 1,185 feet, Plumas County receives approximately 30.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Kabocha to ensure they mature before fall.

Plumas County, CA (Zone 7b) Short season
141 days
Last Spring Frost May 20
141 growing days
First Fall Frost October 8

Plumas County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Apr 13 Transplant: May 25 🍅 Harvest: Aug 24 – Sep 21
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Apr 22 Transplant: Jun 3 🍅 Harvest: Sep 2 – Sep 30
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: May 11 Transplant: Jun 22 🍅 Harvest: Sep 21 – Oct 19

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 Plumas County

How your county's soil matches Kabocha's growing requirements.

Soil pH

Your soil pH (6.6–7.6) overlaps with Kabocha's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Plumas County is excellent for Kabocha — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Kabocha.

How to Plant Kabocha

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 120 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Kabocha

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

Month Kabocha Needs Rainfall You Supplement Action
Jan 6.9" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 5" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 3" 0" ❄️ Dormant
Dec 4.8" 0" ❄️ Dormant

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

Kabocha 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.

Kabocha needs ~1,064 GDD — county provides 1,621 GDD Excellent fit

Kabocha Planting Timeline — Plumas County, CA

Kabocha Planting Calendar

Activity When Date Range
Start Indoors April 22 Apr 22 – May 6
Transplant Outdoors June 3 Jun 3 – Jun 17
Direct Sow May 27 May 27 – Jun 17
Harvest September 2 Sep 2 – Sep 30

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

85–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

141 days in Plumas County

Growing Tips for Kabocha in Plumas County

Direct sow Kabocha outdoors after May 20 in Plumas County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow after frost or start indoors. Harvest when the skin is hard and dull. The stem should be dry and corky. Stores well for 3-4 months in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kabocha in Plumas County, CA?

Plumas County is in Zone 7b with an average last frost of May 20. Plan your Kabocha planting based on this frost date — see the calendar above for exact timing.

What planting zone is Plumas County, CA?

Plumas County, California is in USDA Hardiness Zone 7b. The average last spring frost is May 20 and first fall frost is October 8.

🌱

Your Plumas County Garden Planner — Free

A 24-page printable planner built for Plumas County (Zone 7b). 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 Plumas 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.