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When to Plant Acorn Squash in Jefferson County, IN

Jefferson County, Indiana Zone 6b May

May to-do list for Jefferson County, Indiana

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Jefferson County, Indiana.

Avg. last frost April 10
Avg. first frost October 21
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Fire up the seed-starting tray: acorn squash

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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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.

Jefferson County, Indiana is in USDA Zone 6b. 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 1,010 feet, Jefferson County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Acorn Squash during the growing season.

Jefferson County, IN (Zone 6b) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21
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Jefferson 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 (61 days to spare)
Start indoors: Mar 2 Transplant: Apr 20 🍅 Harvest: Jul 13 – Aug 17
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Mar 6 Transplant: Apr 24 🍅 Harvest: Jul 17 – Aug 21
Safe Start (90%) ✓ Fits season (54 days to spare)
Start indoors: Mar 24 Transplant: May 12 🍅 Harvest: Aug 4 – 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 Jefferson 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 Jefferson County is excellent for Acorn Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.0%) — Acorn Squash will thrive.

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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 666 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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.8" 3.1" 1.7" 💧 Light watering
May 4.8" 4.3" 0.5" 💧 Light watering
Jun 4.8" 4.3" 0.5" 💧 Light watering
Jul 4.8" 3.2" 1.6" 💧 Light watering
Aug 4.8" 3.8" 1" 💧 Light watering
Sep 4.8" 2.8" 2" 💧 Light watering
Oct 4.8" 2.2" 2.6" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jefferson 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 ~1,575 GDD — county provides 3,395 GDD Excellent fit

Acorn Squash Planting Timeline — Jefferson County, IN

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
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
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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 6b

📆 Growing Season

194 days in Jefferson County

Growing Tips for Acorn Squash in Jefferson County

Direct sow Acorn Squash outdoors after April 10 in Jefferson 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 Jefferson County, IN?

Jefferson County is in Zone 6b 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 Jefferson County, IN?

Jefferson County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 21.

🌱

Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson 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 Jefferson County, IN. 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.