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When to Plant Butternut Squash in Sussex County, NJ

Sussex County, New Jersey Zone 6b May

Top priorities for Sussex County, New Jersey gardeners in May

Each item below is timed to Sussex County, New Jersey's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 29
Avg. first frost November 12
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Begin indoor sowing: butternut squash

    Label every cell. You will absolutely forget which is which otherwise.

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Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.

Sussex County, New Jersey is in USDA Zone 6b. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.

At an elevation of 174 feet, Sussex County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Butternut Squash during the growing season.

Sussex County, NJ (Zone 6b) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Sussex 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 (88 days to spare)
Start indoors: Feb 18 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 12
Recommended (50%) ✓ Fits season (88 days to spare)
Start indoors: Feb 22 Transplant: Apr 12 🍅 Harvest: Jul 12 – Aug 16
Safe Start (90%) ✓ Fits season (97 days to spare)
Start indoors: Mar 5 Transplant: Apr 23 🍅 Harvest: Jul 23 – Aug 27

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 Sussex County

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

Soil pH

Your soil pH (4.8–6.4) is more acidic than Butternut Squash prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Butternut Squash.

How to Plant Butternut Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 774 gal / 100 sq ft

Monthly Watering Guide for Butternut Squash

Butternut 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 Butternut Squash Needs Rainfall You Supplement Action
Jan 2.6" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 4.8" 3.1" 1.7" 💧 Light watering
Apr 4.8" 3.1" 1.7" 💧 Light watering
May 4.8" 3.2" 1.6" 💧 Light watering
Jun 4.8" 3.4" 1.4" 💧 Light watering
Jul 4.8" 3.9" 0.9" 💧 Light watering
Aug 4.8" 3.8" 1" 💧 Light watering
Sep 4.8" 3.1" 1.7" 💧 Light watering
Oct 4.8" 3.4" 1.4" 💧 Light watering
Nov 4.8" 3.5" 1.3" 💧 Light watering
Dec 3.4" 0" ❄️ Dormant

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

Butternut 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.

Butternut Squash needs ~1,414 GDD — county provides 3,306 GDD Excellent fit

Butternut Squash Planting Timeline — Sussex County, NJ

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors April 12 Apr 12 – Apr 26
Direct Sow April 5 Apr 5 – Apr 26
Harvest July 12 Jul 12 – Aug 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

228 days in Sussex County

Growing Tips for Butternut Squash in Sussex County

Direct sow Butternut Squash outdoors after March 29 in Sussex County when soil has warmed and frost danger has passed.

Common pests for Butternut 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

Start seeds indoors 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Sussex County, NJ?

Sussex County is in Zone 6b with an average last frost of March 29. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sussex County, NJ?

Sussex County, New Jersey is in USDA Hardiness Zone 6b. The average last spring frost is March 29 and first fall frost is November 12.

🌱

Your Sussex County Garden Planner — Free

A 24-page printable planner built for Sussex 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 Sussex County, NJ. 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.