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When to plant Kabocha in Larimer County County,

Larimer County County gardeners should plant Kabocha between May 9 and May 30 in spring. With Larimer County County's Zone 5b climate (last frost May 2), Kabocha needs 100 days to mature — plant by June 28 for a full harvest.

When to Plant Kabocha in Larimer County, CO

Larimer County, Colorado Zone 5b June

Your June game plan for Larimer County, Colorado

A quick June briefing for Larimer County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 2
Avg. first frost October 6
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 14.9 hrs
  1. Time to start kabocha inside

    These need a head start before your last frost (May 2). Sow into cells now so you're ready to transplant in a few weeks.

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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.

Larimer County, Colorado is in USDA Zone 5b. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.

At an elevation of 7,108 feet, Larimer County receives approximately 23.4 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Kabocha to ensure they mature before fall.

Larimer County, CO (Zone 5b) Moderate season
157 days
Last Spring Frost May 2
157 growing days
First Fall Frost October 6

Larimer County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.2

Drainage

Well Drained

Kabocha Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Start indoors: Mar 24 Transplant: May 12 🍅 Harvest: Aug 11 – Sep 8
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Aug 15 – Sep 12
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Apr 16 Transplant: Jun 4 🍅 Harvest: Sep 3 – Oct 1

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 Larimer County

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

Soil pH

Your soil pH (6.4–8.2) overlaps with Kabocha's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Kabocha.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Kabocha.

How to Plant Kabocha

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

Kabocha Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,130 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 1.7" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 4.3" 2.5" 1.8" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 2.3" 2" 💧 Light watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 1.7" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Larimer 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 ~1,202 GDD — county provides 2,041 GDD Excellent fit

Kabocha Planting Timeline — Larimer County, CO

Kabocha Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest August 15 Aug 15 – Sep 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

85–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

157 days in Larimer County

Growing Tips for Kabocha in Larimer County

Direct sow Kabocha outdoors after May 02 in Larimer 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.

Larimer County receives only 23" of rain annually. Kabocha needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Larimer County, CO?

Larimer County is in Zone 5b with an average last frost of May 2. Plan your Kabocha planting based on this frost date — see the calendar above for exact timing.

What planting zone is Larimer County, CO?

Larimer County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 2 and first fall frost is October 6.

When should I plant Kabocha in Larimer County, ?

In Larimer County, , plant Kabocha after the last frost (around May 2) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Larimer County, for Kabocha?

Larimer County sits in USDA Zone 5b. Kabocha grows reliably in zones 3a through 11b, so it's a good fit here.

Can Kabocha grow in Larimer County's climate?

Yes — Kabocha grows well in Larimer County's temperate climate. Larimer County averages a 157-day frost-free season, with last frost around May 2 and first frost around October 6.

🌱

Your Larimer County Garden Planner — Free

A 22-page printable planner built for Larimer County (Zone 5b). 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 Larimer County, CO. 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.