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When to Plant Acorn Squash in Middlesex County, MA

Middlesex County, Massachusetts Zone 6b May

Your May game plan for Middlesex County, Massachusetts

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

Avg. last frost April 24
Avg. first frost October 17
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Plant out acorn squash

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

  2. Seed acorn squash outdoors

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

  3. Fire up the seed-starting tray: acorn squash

    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.

Middlesex County, Massachusetts is in USDA Zone 6b. 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 117 feet, Middlesex County receives approximately 43.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Acorn Squash during the growing season.

Middlesex County, MA (Zone 6b) Moderate season
176 days
Last Spring Frost April 24
176 growing days
First Fall Frost October 17
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Middlesex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Mar 16 Transplant: May 4 🍅 Harvest: Jul 27 – Aug 31
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Mar 20 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 4
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Apr 8 Transplant: May 27 🍅 Harvest: Aug 19 – Sep 23

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 Middlesex County

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

Soil pH

Your soil pH (5.2–6.7) overlaps with Acorn Squash's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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 176-day season

Sow every 9.1 weeks. Last sowing by Jul 09 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 112 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 3.5" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.8" 3.2" 1.6" 💧 Light watering
May 4.8" 4.2" 0.6" 💧 Light watering
Jun 4.8" 3.6" 1.2" 💧 Light watering
Jul 4.8" 3.9" 0.9" 💧 Light watering
Aug 4.8" 3.9" 0.9" 💧 Light watering
Sep 4.8" 3.3" 1.5" 💧 Light watering
Oct 4.8" 3.5" 1.3" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Middlesex 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 3,080 GDD Excellent fit

Acorn Squash Planting Timeline — Middlesex County, MA

Acorn 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 July 31 Jul 31 – Sep 4

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 Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

176 days in Middlesex County

Growing Tips for Acorn Squash in Middlesex County

Direct sow Acorn Squash outdoors after April 24 in Middlesex 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 Middlesex County, MA?

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

What planting zone is Middlesex County, MA?

Middlesex County, Massachusetts is in USDA Hardiness Zone 6b. The average last spring frost is April 24 and first fall frost is October 17.

🌱

Your Middlesex County Garden Planner — Free

A 24-page printable planner built for Middlesex 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 Middlesex 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.