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When to Plant Acorn Squash in Alexander County, IL

Alexander County, Illinois Zone 7a May

Top priorities for Alexander County, Illinois gardeners in May

A quick May briefing for Alexander County, Illinois gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 10
Avg. first frost October 21
Soil temp (4") 66°F
Watering Low
Pest pressure Moderate
Daylight 14 hrs
  1. Get acorn squash seeds going inside

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

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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.

Alexander County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.

At an elevation of 1,260 feet, Alexander County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Acorn Squash during the growing season.

Alexander County, IL (Zone 7a) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21

Alexander County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Mar 8 Transplant: Apr 19 🍅 Harvest: Jul 12 – Aug 16
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Mar 13 Transplant: Apr 24 🍅 Harvest: Jul 17 – Aug 21
Safe Start (90%) ✓ Fits season (59 days to spare)
Start indoors: Mar 27 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 4

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 Alexander County

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

Soil pH

Your soil pH (5.9–7.0) is within Acorn Squash's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Acorn Squash.

How to Plant Acorn Squash

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

Succession Planting Acorn Squash

2
successive plantings in your 194-day season

Sow every 9.1 weeks. Last sowing by Jul 13 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 548 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4.8" 4.3" 0.5" 💧 Light watering
May 4.8" 4.1" 0.7" 💧 Light watering
Jun 4.8" 5.1" 0" ✅ Rainfall sufficient
Jul 4.8" 3.8" 1" 💧 Light watering
Aug 4.8" 4.8" 0" ✅ Rainfall sufficient
Sep 4.8" 3" 1.8" 💧 Light watering
Oct 4.8" 3" 1.8" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Alexander 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 3,104 GDD Excellent fit

Acorn Squash Planting Timeline — Alexander County, IL

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 17 Apr 17 – May 8
Harvest July 17 Jul 17 – Aug 21

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: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Alexander County

Growing Tips for Acorn Squash in Alexander County

Direct sow Acorn Squash outdoors after April 10 in Alexander 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 Alexander County, IL?

Alexander County is in Zone 7a with an average last frost of April 10. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alexander County, IL?

Alexander County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 21.

🌱

Your Alexander County Garden Planner — Free

A 24-page printable planner built for Alexander 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 Alexander 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.