Blog

When to Plant Acorn Squash in Allamakee County, IA

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.

Allamakee County, Iowa is in USDA Zone 4b. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 804 feet, Allamakee County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Acorn Squash to ensure they mature before fall.

Allamakee County, IA (Zone 4b) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Allamakee County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Mar 13 Transplant: May 15 🍅 Harvest: Aug 7 – Sep 11
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Mar 21 Transplant: May 23 🍅 Harvest: Aug 15 – Sep 19
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Apr 3 Transplant: Jun 5 🍅 Harvest: Aug 28 – Oct 2

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 Allamakee County

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

Soil pH

Your soil pH (5.9โ€“7.1) overlaps with Acorn Squash's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Allamakee County is excellent for Acorn Squash โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.7%) โ€” Acorn Squash will thrive.

How to Plant Acorn Squash

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

Succession Planting Acorn Squash

2
successive plantings in your 158-day season

Sow every 9.1 weeks. Last sowing by Jun 29 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.1″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 66 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 4" 0" โ„๏ธ Dormant
May 4.8" 4.3" 0.5" ๐Ÿ’ง Light watering
Jun 4.8" 5.3" 0" โœ… Rainfall sufficient
Jul 4.8" 4.6" 0.2" ๐Ÿ’ง Light watering
Aug 4.8" 4.2" 0.6" ๐Ÿ’ง Light watering
Sep 4.8" 3.4" 1.4" ๐Ÿ’ง Light watering
Oct 4.8" 2.9" 1.9" ๐Ÿ’ง Light watering
Nov โ€” 3" 0" โ„๏ธ Dormant
Dec โ€” 2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Allamakee County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,035 GDD — county provides 1,817 GDD Excellent fit

Acorn Squash Planting Timeline โ€” Allamakee County, IA

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 โ€“ Apr 4
Transplant Outdoors May 23 May 23 โ€“ Jun 6
Direct Sow May 16 May 16 โ€“ Jun 6
Harvest August 15 Aug 15 โ€“ Sep 19

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

80โ€“100 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

158 days in Allamakee County

Growing Tips for Acorn Squash in Allamakee County

Direct sow Acorn Squash outdoors after May 02 in Allamakee 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 Allamakee County, IA?

Allamakee County is in Zone 4b with an average last frost of May 2. Plan your Acorn Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Allamakee County, IA?

Allamakee County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 2 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Allamakee County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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