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When to plant Squash (Summer) in Black Hawk County, IA

For Black Hawk County, gardeners: plant Squash (Summer) May 6 through May 27 once soil reads 50°F.

When to Plant Squash (Summer) in Black Hawk County, IA

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Black Hawk County, Iowa is in USDA Zone 5a. The average last spring frost is April 29 and the first fall frost is October 7, giving you a growing season of approximately 161 days.

At an elevation of 1,380 feet, Black Hawk County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Squash (Summer) to ensure they mature before fall.

Black Hawk County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 29
161 growing days
First Fall Frost October 7

Black Hawk County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Squash (Summer) Planting Timeline — Black Hawk County, IA

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest July 1 Jul 1 – Sep 2

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 Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

161 days in Black Hawk County

Growing Tips for Black Hawk County

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Black Hawk County, IA?

Black Hawk County is in Zone 5a with an average last frost of April 29. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Black Hawk County, IA?

Black Hawk County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 29 and first fall frost is October 7.

When should I plant Squash (Summer) in Black Hawk County, IA?

In Black Hawk County, IA, plant Squash (Summer) after the last frost (around April 29) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Black Hawk County, IA for Squash (Summer)?

Black Hawk County sits in USDA Zone 5a. Squash (Summer) grows reliably in zones 3a through 11b, so it's a good fit here.

Can Squash (Summer) grow in Black Hawk County's climate?

Yes — Squash (Summer) grows well in Black Hawk County's temperate climate. Black Hawk County averages a 161-day frost-free season, with last frost around April 29 and first frost around October 7.

🌱

Your Black Hawk County Garden Planner — Free

A 22-page printable planner built for Black Hawk 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.

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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 Black Hawk County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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