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When to Plant Hubbard Squash in Warren County, NJ

Warren County, New Jersey Zone 6b May

May in the garden — Warren County, New Jersey

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Warren County, New Jersey.

Avg. last frost April 16
Avg. first frost October 27
Soil temp (4") 61°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Start hubbard squash under lights

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Warren County, New Jersey is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 27, giving you a growing season of approximately 194 days.

At an elevation of 369 feet, Warren County receives approximately 48.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Hubbard Squash during the growing season.

Warren County, NJ (Zone 6b) Moderate season
194 days
Last Spring Frost April 16
194 growing days
First Fall Frost October 27

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Mar 2 Transplant: Apr 20 🍅 Harvest: Aug 3 – Sep 7
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Mar 12 Transplant: Apr 30 🍅 Harvest: Aug 13 – Sep 17
Safe Start (90%) ✓ Fits season (36 days to spare)
Start indoors: Apr 4 Transplant: May 23 🍅 Harvest: Sep 5 – Oct 10

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 Warren County

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

Soil pH

Your soil pH (5.2–6.4) is more acidic than Hubbard Squash prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Hubbard Squash.

How to Plant Hubbard Squash

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

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 Hubbard Squash

Hubbard Squash needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Hubbard Squash Needs Rainfall You Supplement Action
Jan 4" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 4.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.3" 0" ✅ Rainfall sufficient
Nov 3.4" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

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

Hubbard 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.

Hubbard Squash needs ~1,595 GDD — county provides 2,813 GDD Excellent fit

Hubbard Squash Planting Timeline — Warren County, NJ

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 23 Apr 23 – May 14
Harvest August 13 Aug 13 – Sep 17

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Warren County

Growing Tips for Hubbard Squash in Warren County

Direct sow Hubbard Squash outdoors after April 16 in Warren County when soil has warmed and frost danger has passed.

Common pests for Hubbard 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 in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hubbard Squash in Warren County, NJ?

Warren County is in Zone 6b with an average last frost of April 16. Plan your Hubbard Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, NJ?

Warren County, New Jersey is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 27.

🌱

Your Warren County Garden Planner — Free

A 24-page printable planner built for Warren 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 Warren 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.