Blog

When to Plant Butternut Squash in Davis County, IA

Davis County, Iowa Zone 5b May

This month in Davis County, Iowa

Your garden in Davis County, Iowa is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 19
Avg. first frost October 16
Soil temp (4") 60°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Move butternut squash from tray to bed

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Indoor seed-starting week for butternut squash

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

Instant PDF download. No spam, unsubscribe any time.

Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.

Davis County, Iowa is in USDA Zone 5b. The average last spring frost is April 19 and the first fall frost is October 16, giving you a growing season of approximately 180 days.

At an elevation of 859 feet, Davis County receives approximately 30.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Butternut Squash during the growing season.

Davis County, IA (Zone 5b) Moderate season
180 days
Last Spring Frost April 19
180 growing days
First Fall Frost October 16
Share this guide:

Davis County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (40 days to spare)
Start indoors: Mar 9 Transplant: Apr 27 🍅 Harvest: Jul 27 – Aug 31
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Mar 15 Transplant: May 3 🍅 Harvest: Aug 2 – Sep 6
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Mar 29 Transplant: May 17 🍅 Harvest: Aug 16 – Sep 20

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 Davis County

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

Soil pH

Your soil pH (6.2–6.7) is within Butternut Squash's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

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

How to Plant Butternut Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 630 gal / 100 sq ft

Monthly Watering Guide for Butternut Squash

Butternut 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 Butternut Squash Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.8" 2.9" 1.9" 💧 Light watering
May 4.8" 3.7" 1.1" 💧 Light watering
Jun 4.8" 4" 0.8" 💧 Light watering
Jul 4.8" 3.6" 1.2" 💧 Light watering
Aug 4.8" 2.6" 2.2" 💧 Light watering
Sep 4.8" 2.3" 2.5" 🚿 Regular watering
Oct 4.8" 2.5" 2.3" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

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

Butternut 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.

Butternut Squash needs ~1,341 GDD — county provides 2,475 GDD Excellent fit

Butternut Squash Planting Timeline — Davis County, IA

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors May 3 May 3 – May 17
Direct Sow April 26 Apr 26 – May 17
Harvest August 2 Aug 2 – Sep 6

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

180 days in Davis County

Growing Tips for Butternut Squash in Davis County

Direct sow Butternut Squash outdoors after April 19 in Davis County when soil has warmed and frost danger has passed.

Common pests for Butternut 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 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Davis County, IA?

Davis County is in Zone 5b with an average last frost of April 19. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Davis County, IA?

Davis County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 19 and first fall frost is October 16.

🌱

Your Davis County Garden Planner — Free

A 24-page printable planner built for Davis County (Zone 5b). 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 Davis County, IA. 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.