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When to Plant Acorn Squash in Jefferson County, PA

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.

Jefferson County, Pennsylvania is in USDA Zone 5a. The average last spring frost is May 18 and the first fall frost is October 7, giving you a growing season of approximately 142 days.

At an elevation of 1,026 feet, Jefferson County receives approximately 42.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Acorn Squash to ensure they mature before fall.

Jefferson County, PA (Zone 5a) Short season
142 days
Last Spring Frost May 18
142 growing days
First Fall Frost October 7

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Apr 4 Transplant: May 23 🍅 Harvest: Aug 15 – Sep 19
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 13 Transplant: Jun 1 🍅 Harvest: Aug 24 – Sep 28
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Apr 27 Transplant: Jun 15 🍅 Harvest: Sep 7 – Oct 12

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 Jefferson County

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

Soil pH

Your soil pH (4.8โ€“6.4) overlaps with Acorn Squash's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Jefferson County is excellent for Acorn Squash โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.0%) โ€” Acorn Squash will thrive.

How to Plant Acorn Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 2.5" 0" โ„๏ธ Dormant
Feb โ€” 2.7" 0" โ„๏ธ Dormant
Mar โ€” 3.9" 0" โ„๏ธ Dormant
Apr โ€” 3.8" 0" โ„๏ธ Dormant
May 4.8" 4.1" 0.7" ๐Ÿ’ง Light watering
Jun 4.8" 4.3" 0.5" ๐Ÿ’ง Light watering
Jul 4.8" 4.7" 0.1" ๐Ÿ’ง Light watering
Aug 4.8" 3.8" 1" ๐Ÿ’ง Light watering
Sep 4.8" 3.2" 1.6" ๐Ÿ’ง Light watering
Oct 4.8" 3.2" 1.6" ๐Ÿ’ง Light watering
Nov โ€” 3.4" 0" โ„๏ธ Dormant
Dec โ€” 3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Jefferson County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,102 GDD — county provides 1,739 GDD Excellent fit

Acorn Squash Planting Timeline โ€” Jefferson County, PA

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 โ€“ Apr 27
Transplant Outdoors June 1 Jun 1 โ€“ Jun 15
Direct Sow May 25 May 25 โ€“ Jun 15
Harvest August 24 Aug 24 โ€“ Sep 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Direct Sow
June Transplant Outdoors Direct Sow
July โ€”
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“100 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

142 days in Jefferson County

Growing Tips for Acorn Squash in Jefferson County

Direct sow Acorn Squash outdoors after May 18 in Jefferson 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 Jefferson County, PA?

Jefferson County is in Zone 5a with an average last frost of May 18. Plan your Acorn Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, PA?

Jefferson County, Pennsylvania is in USDA Hardiness Zone 5a. The average last spring frost is May 18 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Jefferson County, PA. Local conditions may vary. Last updated: April 2026.