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When to Plant Acorn Squash in Hardin County, IL

Hardin County, Illinois Zone 7a May

May to-do list for Hardin County, Illinois

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 4
Avg. first frost October 31
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Time to start acorn squash inside

    Label every cell. You will absolutely forget which is which otherwise.

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Acorn squash is a small winter squash with dark green, ribbed skin and mildly sweet orange flesh. It is perfect for stuffing and roasting as individual servings.

Hardin County, Illinois is in USDA Zone 7a. The average last spring frost is April 4 and the first fall frost is October 31, giving you a growing season of approximately 210 days.

At an elevation of 1,218 feet, Hardin County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Acorn Squash during the growing season.

Hardin County, IL (Zone 7a) Long season
210 days
Last Spring Frost April 4
210 growing days
First Fall Frost October 31

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Feb 28 Transplant: Apr 11 🍅 Harvest: Jul 4 – Aug 8
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Mar 7 Transplant: Apr 18 🍅 Harvest: Jul 11 – Aug 15
Safe Start (90%) ✓ Fits season (85 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jul 24 – Aug 28

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 Hardin County

How your county's soil matches Acorn Squash's growing requirements.

Soil pH

Your soil pH (6.2–7.2) overlaps with Acorn Squash's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Acorn Squash will thrive.

How to Plant Acorn Squash

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

Succession Planting Acorn Squash

3
successive plantings in your 210-day season

Sow every 9.1 weeks. Last sowing by Jul 23 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 927 gal / 100 sq ft

Monthly Watering Guide for Acorn Squash

Acorn Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Acorn Squash Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.8" 3.2" 1.6" 💧 Light watering
May 4.8" 3.1" 1.7" 💧 Light watering
Jun 4.8" 3.4" 1.4" 💧 Light watering
Jul 4.8" 3" 1.8" 💧 Light watering
Aug 4.8" 3.4" 1.4" 💧 Light watering
Sep 4.8" 2.8" 2" 💧 Light watering
Oct 4.8" 2.7" 2.1" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Acorn Squash 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.

Acorn Squash needs ~1,440 GDD — county provides 3,360 GDD Excellent fit

Acorn Squash Planting Timeline — Hardin County, IL

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 11 Apr 11 – May 2
Harvest July 11 Jul 11 – Aug 15

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

1.1"/week · 1-2 times/week

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

210 days in Hardin County

Growing Tips for Acorn Squash in Hardin County

Direct sow Acorn Squash outdoors after April 04 in Hardin County when soil has warmed and frost danger has passed.

Common pests for Acorn Squash 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 last frost. Harvest when the ground spot turns orange and the skin is hard. Acorn squash has a shorter storage life than butternut, lasting about 2 months.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Acorn Squash in Hardin County, IL?

Hardin County is in Zone 7a with an average last frost of April 4. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardin County, IL?

Hardin County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 4 and first fall frost is October 31.

🌱

Your Hardin County Garden Planner — Free

A 24-page printable planner built for Hardin County (Zone 7a). 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 Hardin County, IL. 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.