Blog

When to Plant Squash (Summer) in Marshall County, IN

Marshall County, Indiana Zone 6a May

Marshall County, Indiana gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Marshall County, Indiana this May and put them front and centre. Tackle them in order.

Avg. last frost April 26
Avg. first frost October 18
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Transplant squash (summer) outside

    Frost risk is low now in Marshall County, Indiana. If you've been covering beds overnight, you can stop.

  2. Outdoor sowing time: squash (summer)

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

  3. Start squash (summer) under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

June will be here before you know it — start on
  • First harvests: squash (summer)

Instant PDF download. No spam, unsubscribe any time.

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Marshall County, Indiana is in USDA Zone 6a. The average last spring frost is April 26 and the first fall frost is October 18, giving you a growing season of approximately 175 days.

At an elevation of 1,140 feet, Marshall County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Squash (Summer) to ensure they mature before fall.

Marshall County, IN (Zone 6a) Moderate season
175 days
Last Spring Frost April 26
175 growing days
First Fall Frost October 18

Marshall County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Start indoors: Mar 16 Transplant: May 4 🍅 Harvest: Jun 22 – Aug 24
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Mar 22 Transplant: May 10 🍅 Harvest: Jun 28 – Aug 30
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Apr 7 Transplant: May 26 🍅 Harvest: Jul 14 – Sep 15

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 Marshall County

How your county's soil matches Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (6.2–7.3) is within Squash (Summer)'s preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Marshall County is excellent for Squash (Summer) — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Squash (Summer).

Organic Matter

Organic matter is excellent (5.1%) — Squash (Summer) will thrive.

How to Plant Squash (Summer)

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

Succession Planting Squash (Summer)

4
successive plantings in your 175-day season

Sow every 5.1 weeks. Last sowing by Aug 14 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 735 gal / 100 sq ft

Monthly Watering Guide for Squash (Summer)

Squash (Summer) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Squash (Summer) Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Squash (Summer) 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.

Squash (Summer) needs ~715 GDD — county provides 2,275 GDD Excellent fit

Squash (Summer) Planting Timeline — Marshall County, IN

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest June 28 Jun 28 – Aug 30

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 Harvest
July Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

175 days in Marshall County

Growing Tips for Squash (Summer) in Marshall County

Direct sow Squash (Summer) outdoors after April 26 in Marshall County when soil has warmed and frost danger has passed.

Your generous 175.0-day season in Marshall County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.

Common pests for Squash (Summer) 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 on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Marshall County, IN?

Marshall County is in Zone 6a with an average last frost of April 26. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, IN?

Marshall County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 26 and first fall frost is October 18.

🌱

Your Marshall County Garden Planner — Free

A 24-page printable planner built for Marshall 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Marshall 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.