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When to Plant Acorn Squash in Philadelphia County, PA

Philadelphia County, Pennsylvania Zone 7b May

May in the garden — Philadelphia County, Pennsylvania

May is a pivotal month for Philadelphia County, Pennsylvania gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 16
Avg. first frost October 24
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 14.2 hrs
  1. Start acorn squash under lights

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

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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.

Philadelphia County, Pennsylvania is in USDA Zone 7b. The average last spring frost is April 16 and the first fall frost is October 24, giving you a growing season of approximately 191 days.

At an elevation of 996 feet, Philadelphia County receives approximately 48.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Acorn Squash during the growing season.

Philadelphia County, PA (Zone 7b) Moderate season
191 days
Last Spring Frost April 16
191 growing days
First Fall Frost October 24
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Philadelphia 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 (55 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jul 20 – Aug 24
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: Jul 23 – Aug 27
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Apr 13 Transplant: May 25 🍅 Harvest: Aug 17 – Sep 21

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 Philadelphia 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 Philadelphia County is excellent for Acorn Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (4.0%). 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 191-day season

Sow every 9.1 weeks. Last sowing by Jul 16 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.1″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 68 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 3.9" 0" ❄️ Dormant
Feb 3.7" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 4.8" 4.5" 0.3" 💧 Light watering
May 4.8" 4.5" 0.3" 💧 Light watering
Jun 4.8" 3.9" 0.9" 💧 Light watering
Jul 4.8" 4.5" 0.3" 💧 Light watering
Aug 4.8" 4.5" 0.3" 💧 Light watering
Sep 4.8" 3.6" 1.2" 💧 Light watering
Oct 4.8" 4.3" 0.5" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Philadelphia 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 ~1,778 GDD — county provides 3,772 GDD Excellent fit

Acorn Squash Planting Timeline — Philadelphia County, PA

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 23 Apr 23 – May 14
Harvest July 23 Jul 23 – Aug 27

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors 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 · Only during dry spells

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

191 days in Philadelphia County

Growing Tips for Acorn Squash in Philadelphia County

Direct sow Acorn Squash outdoors after April 16 in Philadelphia 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 Philadelphia County, PA?

Philadelphia County is in Zone 7b with an average last frost of April 16. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Philadelphia County, PA?

Philadelphia County, Pennsylvania is in USDA Hardiness Zone 7b. The average last spring frost is April 16 and first fall frost is October 24.

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Your Philadelphia County Garden Planner — Free

A 24-page printable planner built for Philadelphia County (Zone 7b). 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 Philadelphia County, PA. 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.