Blog

When to Plant Squash (Winter) in Coos County, NH

Coos County, New Hampshire Zone 4b April

Your April planting checklist for Coos County, New Hampshire

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

Avg. last frost May 18
Avg. first frost September 30
Soil temp (4") 41°F
Watering Moderate
Pest pressure Low
Daylight 13.3 hrs

Instant PDF download. No spam, unsubscribe any time.

Winter squash includes butternut, acorn, delicata, and hubbard varieties grown to full maturity with hard rinds for storage. They develop sweet, dense flesh.

Coos County, New Hampshire is in USDA Zone 4b. The average last spring frost is May 18 and the first fall frost is September 30, giving you a growing season of approximately 135 days.

At an elevation of 604 feet, Coos County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Squash (Winter) to ensure they mature before fall.

Coos County, NH (Zone 4b) Short season
135 days
Last Spring Frost May 18
135 growing days
First Fall Frost September 30
Share this guide:

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 30 Transplant: Jun 1 🍅 Harvest: Aug 24 – Oct 19
Recommended (50%) ✗ May not fit
Start indoors: Apr 6 Transplant: Jun 8 🍅 Harvest: Aug 31 – Oct 26
Safe Start (90%) ✗ May not fit
Start indoors: Apr 21 Transplant: Jun 23 🍅 Harvest: Sep 15 – Nov 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 Coos County

How your county's soil matches Squash (Winter)'s growing requirements.

Soil pH

Your soil pH (5.2–6.6) is more acidic than Squash (Winter) prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Coos County is excellent for Squash (Winter) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Squash (Winter).

How to Plant Squash (Winter)

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Squash (Winter)

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

Month Squash (Winter) Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 3.1" 0" ❄️ Dormant
Nov 3.1" 0" ❄️ Dormant
Dec 3.3" 0" ❄️ Dormant

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

Squash (Winter) 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.

Squash (Winter) needs ~1,300 GDD — county provides 1,755 GDD Excellent fit

Squash (Winter) Planting Timeline — Coos County, NH

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 – Apr 20
Transplant Outdoors June 8 Jun 8 – Jun 22
Direct Sow June 1 Jun 1 – Jun 22
Harvest August 31 Aug 31 – Oct 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 4b

📆 Growing Season

135 days in Coos County

Growing Tips for Squash (Winter) in Coos County

Direct sow Squash (Winter) outdoors after May 18 in Coos County when soil has warmed and frost danger has passed.

Common pests for Squash (Winter) 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 on rich mounds. Allow ample space for sprawling vines. Cure harvested fruits in the sun for 10 days before storing in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Winter) in Coos County, NH?

Coos County is in Zone 4b with an average last frost of May 18. Plan your Squash (Winter) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coos County, NH?

Coos County, New Hampshire is in USDA Hardiness Zone 4b. The average last spring frost is May 18 and first fall frost is September 30.

🌱

Your Coos County Garden Planner — Free

A 24-page printable planner built for Coos County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Coos County, NH. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.