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When to Plant Squash (Summer) in Plymouth County, MA

Plymouth County, Massachusetts Zone 6b May

May in the garden — Plymouth County, Massachusetts

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 18
Avg. first frost October 26
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Transplant squash (summer) outside

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Time to start squash (summer) inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

To set up a strong June, finish these tasks
  • First harvests: squash (summer)

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

Plymouth County, Massachusetts is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 26, giving you a growing season of approximately 191 days.

At an elevation of 947 feet, Plymouth County receives approximately 46.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Squash (Summer) during the growing season.

Plymouth County, MA (Zone 6b) Moderate season
191 days
Last Spring Frost April 18
191 growing days
First Fall Frost October 26

Plymouth County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (63 days to spare)
Start indoors: Mar 8 Transplant: Apr 26 🍅 Harvest: Jun 14 – Aug 16
Recommended (50%) ✓ Fits season (65 days to spare)
Start indoors: Mar 14 Transplant: May 2 🍅 Harvest: Jun 20 – Aug 22
Safe Start (90%) ✓ Fits season (64 days to spare)
Start indoors: Mar 24 Transplant: May 12 🍅 Harvest: Jun 30 – Sep 1

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 Plymouth County

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

Soil pH

Your soil pH (4.8–6.6) is more acidic than Squash (Summer) prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Squash (Summer).

How to Plant Squash (Summer)

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

Succession Planting Squash (Summer)

5
successive plantings in your 191-day season

Sow every 5.1 weeks. Last sowing by Aug 22 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 3" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.2" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 3.9" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Plymouth 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 ~962 GDD — county provides 3,342 GDD Excellent fit

Squash (Summer) Planting Timeline — Plymouth County, MA

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest June 20 Jun 20 – Aug 22

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Direct Sow
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 · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

191 days in Plymouth County

Growing Tips for Squash (Summer) in Plymouth County

Direct sow Squash (Summer) outdoors after April 18 in Plymouth County when soil has warmed and frost danger has passed.

Your generous 191.0-day season in Plymouth 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 Plymouth County, MA?

Plymouth County is in Zone 6b with an average last frost of April 18. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Plymouth County, MA?

Plymouth County, Massachusetts is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 26.

🌱

Your Plymouth County Garden Planner — Free

A 24-page printable planner built for Plymouth 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 Plymouth County, MA. 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.