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When to Plant Kabocha in Windsor County, VT

Windsor County, Vermont Zone 5a May

May in Windsor County, Vermont — your action list

May is a pivotal month for Windsor County, Vermont gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost October 7
Soil temp (4") 53°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Time to transplant kabocha

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Put kabocha seeds straight in the ground

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

June will be here before you know it — start on
  • 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.

Windsor County, Vermont is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 7, giving you a growing season of approximately 148 days.

At an elevation of 309 feet, Windsor County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Kabocha to ensure they mature before fall.

Windsor County, VT (Zone 5a) Short season
148 days
Last Spring Frost May 12
148 growing days
First Fall Frost October 7

Windsor County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Apr 1 Transplant: May 20 🍅 Harvest: Aug 19 – Sep 16
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Apr 7 Transplant: May 26 🍅 Harvest: Aug 25 – Sep 22
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 20 Transplant: Jun 8 🍅 Harvest: Sep 7 – Oct 5

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 Windsor County

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

Soil pH

Your soil pH (4.9–6.5) is more acidic than Kabocha prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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
1.4″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 3.2" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3.9" 0" ❄️ Dormant
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 4.6" 0" ✅ Rainfall sufficient
Oct 4.3" 4.5" 0" ✅ Rainfall sufficient
Nov 3.5" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Windsor 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 ~1,133 GDD — county provides 1,813 GDD Excellent fit

Kabocha Planting Timeline — Windsor County, VT

Kabocha Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest August 25 Aug 25 – Sep 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

85–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

148 days in Windsor County

Growing Tips for Kabocha in Windsor County

Direct sow Kabocha outdoors after May 12 in Windsor 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 Windsor County, VT?

Windsor County is in Zone 5a with an average last frost of May 12. Plan your Kabocha planting based on this frost date — see the calendar above for exact timing.

What planting zone is Windsor County, VT?

Windsor County, Vermont is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 7.

🌱

Your Windsor County Garden Planner — Free

A 24-page printable planner built for Windsor County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Windsor County, VT. 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.