Blog

When to plant Butternut Squash in Delaware County, IA

Delaware County's climate puts the Butternut Squash spring window between May 9 and May 30. time plantings around the expected last-frost window for best survival.

When to Plant Butternut Squash in Delaware County, IA

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.

Delaware County, Iowa is in USDA Zone 5a. 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 974 feet, Delaware County receives approximately 31.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Butternut Squash to ensure they mature before fall.

Delaware County, IA (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Delaware County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Butternut Squash Planting Timeline — Delaware County, IA

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest August 15 Aug 15 – Sep 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

158 days in Delaware County

Growing Tips for Delaware County

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 Delaware County, IA?

Delaware County is in Zone 5a with an average last frost of May 2. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Delaware County, IA?

Delaware County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

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

In Delaware County, IA, plant Butternut Squash after the last frost (around May 2) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Delaware County, IA for Butternut Squash?

Delaware County sits in USDA Zone 5a. Butternut Squash grows reliably in zones 3a through 11b, so it's a good fit here.

Can Butternut Squash grow in Delaware County's climate?

Yes — Butternut Squash grows well in Delaware County's temperate climate. Delaware County averages a 158-day frost-free season, with last frost around May 2 and first frost around October 7.

🌱

Your Delaware County Garden Planner — Free

A 22-page printable planner built for Delaware County (Zone 5a). 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 Delaware County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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