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When to Plant Squash (Winter) in Cornucopia, WI

Bayfield County, Wisconsin Zone 4b July

Your July planting checklist for Bayfield County, Wisconsin

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

Avg. last frost May 14
Avg. first frost October 3
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 15.3 hrs

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

Cornucopia, Wisconsin is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is October 3, giving you a growing season of approximately 142 days.

At an elevation of 619 feet, Bayfield County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Squash (Winter) to ensure they mature before fall.

Cornucopia, WI (Zone 4b) Short season
142 days
Last Spring Frost May 14
142 growing days
First Fall Frost October 3

Cornucopia Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Squash (Winter) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 26 Transplant: May 28 🍅 Harvest: Aug 20 – Oct 15
Recommended (50%) ✗ May not fit
Start indoors: Apr 2 Transplant: Jun 4 🍅 Harvest: Aug 27 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: Apr 20 Transplant: Jun 22 🍅 Harvest: Sep 14 – Nov 9

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 Cornucopia

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

Soil pH

Your soil pH (5.8–6.8) overlaps with Squash (Winter)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Squash (Winter) will thrive.

How to Plant Squash (Winter)

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

Squash (Winter) Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Bayfield 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 ~1,000 GDD — county provides 1,420 GDD Excellent fit

Squash (Winter) Planting Timeline — Cornucopia, WI

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors June 4 Jun 4 – Jun 18
Direct Sow May 28 May 28 – Jun 18
Harvest August 27 Aug 27 – Oct 22

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Direct Sow
June Transplant Outdoors Direct Sow
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

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

142 days in Bayfield County

Growing Tips for Squash (Winter) in Cornucopia

Direct sow Squash (Winter) outdoors after May 14 in Bayfield 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 →

🌱

Your Bayfield County Garden Planner — Free

A 22-page printable planner built for Bayfield 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.

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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 Bayfield County, WI. Local conditions may vary. Last updated: July 2026.