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When to Plant Acorn Squash in Rusk County, WI

Rusk County, Wisconsin Zone 4a May

Top priorities for Rusk County, Wisconsin gardeners in May

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

Avg. last frost May 16
Avg. first frost September 28
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Sow acorn squash where they'll grow

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

June will be here before you know it — start on
  • Transplants going out: acorn squash
  • Starting indoors: acorn squash

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Acorn squash is a small winter squash with dark green, ribbed skin and mildly sweet orange flesh. It is perfect for stuffing and roasting as individual servings.

Rusk County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 16 and the first fall frost is September 28, giving you a growing season of approximately 135 days.

At an elevation of 1,112 feet, Rusk County receives approximately 38.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Acorn Squash to ensure they mature before fall.

Rusk County, WI (Zone 4a) Short season
135 days
Last Spring Frost May 16
135 growing days
First Fall Frost September 28
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Rusk County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 30 Transplant: Jun 1 🍅 Harvest: Aug 24 – Sep 28
Recommended (50%) ✗ May not fit
Start indoors: Apr 4 Transplant: Jun 6 🍅 Harvest: Aug 29 – Oct 3
Safe Start (90%) ✗ May not fit
Start indoors: Apr 17 Transplant: Jun 19 🍅 Harvest: Sep 11 – Oct 16

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 Rusk County

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

Soil pH

Your soil pH (6.1–7.0) is within Acorn Squash's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Acorn Squash will thrive.

How to Plant Acorn Squash

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

Plant Water Budget

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

Monthly Watering Guide for Acorn Squash

Acorn 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 Acorn Squash Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 4.8" 4.6" 0.2" 💧 Light watering
Jun 4.8" 4.4" 0.4" 💧 Light watering
Jul 4.8" 4.4" 0.4" 💧 Light watering
Aug 4.8" 3.9" 0.9" 💧 Light watering
Sep 4.8" 3.7" 1.1" 💧 Light watering
Oct 2.8" 0" ❄️ Dormant
Nov 2.9" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Acorn 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.

Acorn Squash needs ~900 GDD — county provides 1,350 GDD Excellent fit

Acorn Squash Planting Timeline — Rusk County, WI

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors June 6 Jun 6 – Jun 20
Direct Sow May 30 May 30 – Jun 20
Harvest August 29 Aug 29 – Oct 3

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

135 days in Rusk County

Growing Tips for Acorn Squash in Rusk County

Direct sow Acorn Squash outdoors after May 16 in Rusk County when soil has warmed and frost danger has passed.

Common pests for Acorn 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

Direct sow after last frost. Harvest when the ground spot turns orange and the skin is hard. Acorn squash has a shorter storage life than butternut, lasting about 2 months.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Acorn Squash in Rusk County, WI?

Rusk County is in Zone 4a with an average last frost of May 16. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rusk County, WI?

Rusk County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 16 and first fall frost is September 28.

🌱

Your Rusk County Garden Planner — Free

A 24-page printable planner built for Rusk County (Zone 4a). 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 Rusk County, WI. 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.