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When to Plant Butternut Squash in Cass County, IN

Cass County, Indiana Zone 6a May

May in the garden — Cass County, Indiana

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 24
Avg. first frost October 17
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Harden off and plant butternut squash

    Your last frost (April 24) has passed. These warm-season crops can handle outdoor soil now.

  2. Direct-sow butternut squash

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

  3. Time to start butternut squash inside

    You're about 20 weeks out from your last frost — the perfect window to get these germinating indoors.

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Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.

Cass County, Indiana is in USDA Zone 6a. The average last spring frost is April 24 and the first fall frost is October 17, giving you a growing season of approximately 176 days.

At an elevation of 703 feet, Cass County receives approximately 36.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Butternut Squash to ensure they mature before fall.

Cass County, IN (Zone 6a) Moderate season
176 days
Last Spring Frost April 24
176 growing days
First Fall Frost October 17
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Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Mar 12 Transplant: Apr 30 🍅 Harvest: Jul 30 – Sep 3
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Mar 20 Transplant: May 8 🍅 Harvest: Aug 7 – Sep 11
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Apr 5 Transplant: May 24 🍅 Harvest: Aug 23 – Sep 27

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 Cass County

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

Soil pH

Your soil pH (5.7–6.8) overlaps with Butternut Squash's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Butternut Squash.

Organic Matter

Organic matter is excellent (4.8%) — Butternut Squash will thrive.

How to Plant Butternut Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 876 gal / 100 sq ft

Monthly Watering Guide for Butternut Squash

Butternut 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 Butternut Squash Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.8" 3.1" 1.7" 💧 Light watering
May 4.8" 4.5" 0.3" 💧 Light watering
Jun 4.8" 5" 0" ✅ Rainfall sufficient
Jul 4.8" 3.8" 1" 💧 Light watering
Aug 4.8" 3.9" 0.9" 💧 Light watering
Sep 4.8" 3.4" 1.4" 💧 Light watering
Oct 4.8" 2.6" 2.2" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Butternut 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.

Butternut Squash needs ~1,194 GDD — county provides 2,156 GDD Excellent fit

Butternut Squash Planting Timeline — Cass County, IN

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 1 May 1 – May 22
Harvest August 7 Aug 7 – Sep 11

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

Month-by-Month Timeline

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

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

176 days in Cass County

Growing Tips for Butternut Squash in Cass County

Direct sow Butternut Squash outdoors after April 24 in Cass County when soil has warmed and frost danger has passed.

Common pests for Butternut 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

Start seeds indoors 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Cass County, IN?

Cass County is in Zone 6a with an average last frost of April 24. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, IN?

Cass County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 24 and first fall frost is October 17.

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Your Cass County Garden Planner — Free

A 24-page printable planner built for Cass County (Zone 6a). 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 Cass 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.