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When to plant Kabocha in Clark County County,

The best window to plant Kabocha in Clark County County, is April 21–May 12, when soil warms to 50°F. Last frost typically hits April 14; first frost October 17.

When to Plant Kabocha in Clark County, IL

Clark County, Illinois Zone 6b June

This month in Clark County, Illinois

Your garden in Clark County, Illinois is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 14
Avg. first frost October 17
Soil temp (4") 75°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
Get ahead of July
  • First harvests: 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.

Clark County, Illinois is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 591 feet, Clark County receives approximately 41.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Kabocha during the growing season.

Clark County, IL (Zone 6b) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Kabocha Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 5 Transplant: Apr 23 🍅 Harvest: Jul 23 – Aug 20
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Mar 10 Transplant: Apr 28 🍅 Harvest: Jul 28 – Aug 25
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Mar 24 Transplant: May 12 🍅 Harvest: Aug 11 – Sep 8

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 Clark County

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

Soil pH

Your soil pH (6.2–6.8) is within Kabocha's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — Kabocha will thrive.

How to Plant Kabocha

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

Kabocha 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 129 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.8" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4" 0.3" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clark 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 ~1,619 GDD — county provides 3,255 GDD Excellent fit

Kabocha Planting Timeline — Clark County, IL

Kabocha Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 21 Apr 21 – May 12
Harvest July 28 Jul 28 – Aug 25

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
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: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

186 days in Clark County

Growing Tips for Kabocha in Clark County

Direct sow Kabocha outdoors after April 14 in Clark 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 Clark County, IL?

Clark County is in Zone 6b with an average last frost of April 14. Plan your Kabocha planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, IL?

Clark County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 17.

When should I plant Kabocha in Clark County, ?

In Clark County, , plant Kabocha after the last frost (around April 14) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Clark County, for Kabocha?

Clark County sits in USDA Zone 6b. Kabocha grows reliably in zones 3a through 11b, so it's a good fit here.

Can Kabocha grow in Clark County's climate?

Yes — Kabocha grows well in Clark County's temperate climate. Clark County averages a 186-day frost-free season, with last frost around April 14 and first frost around October 17.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 6b). 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 Clark County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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