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When to Plant Hubbard Squash in Hillsborough County, NH

Hillsborough County, New Hampshire Zone 6a May

May in the garden — Hillsborough County, New Hampshire

Your Hillsborough County, New Hampshire garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 2
Avg. first frost October 11
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Get hubbard squash in the ground

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Scatter hubbard squash into prepared beds

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

To set up a strong June, finish these tasks
  • Starting indoors: hubbard squash

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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.

Hillsborough County, New Hampshire is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 11, giving you a growing season of approximately 162 days.

At an elevation of 145 feet, Hillsborough County receives approximately 44 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Hubbard Squash to ensure they mature before fall.

Hillsborough County, NH (Zone 6a) Moderate season
162 days
Last Spring Frost May 2
162 growing days
First Fall Frost October 11

Hillsborough County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Aug 24 – Sep 28
Recommended (50%) ✓ Fits season (8 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Aug 29 – Oct 3
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Apr 12 Transplant: May 31 🍅 Harvest: Sep 13 – Oct 18

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 Hillsborough County

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

Soil pH

Your soil pH (4.9–6.6) is more acidic than Hubbard Squash prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Hubbard Squash.

Organic Matter

Organic matter is moderate (3.9%). 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
1.1″/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 3" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 4.4" 0" ❄️ Dormant
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Hillsborough 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 ~1,430 GDD — county provides 2,106 GDD Excellent fit

Hubbard Squash Planting Timeline — Hillsborough County, NH

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest August 29 Aug 29 – Oct 3

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
August Harvest
September Harvest
October Harvest
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 6a

📆 Growing Season

162 days in Hillsborough County

Growing Tips for Hubbard Squash in Hillsborough County

Direct sow Hubbard Squash outdoors after May 02 in Hillsborough 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 Hillsborough County, NH?

Hillsborough County is in Zone 6a with an average last frost of May 2. Plan your Hubbard Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hillsborough County, NH?

Hillsborough County, New Hampshire is in USDA Hardiness Zone 6a. The average last spring frost is May 2 and first fall frost is October 11.

🌱

Your Hillsborough County Garden Planner — Free

A 24-page printable planner built for Hillsborough County (Zone 6a). 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 Hillsborough County, NH. 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.