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When to plant Sweet Corn in Floyd County, IA

The best window to plant Sweet Corn in Floyd County, is May 8–May 29, when soil warms to 50°F. Last frost typically hits May 1; first frost October 7.

When to Plant Sweet Corn in Floyd County, IA

Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.

Floyd County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 714 feet, Floyd County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Sweet Corn to ensure they mature before fall.

Floyd County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Floyd County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Sweet Corn Planting Timeline — Floyd County, IA

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow May 8 May 8 – May 29
Harvest July 10 Jul 10 – Aug 21

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

159 days in Floyd County

Growing Tips for Floyd County

Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Floyd County, IA?

Floyd County is in Zone 5a with an average last frost of May 1. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Floyd County, IA?

Floyd County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 7.

When should I plant Sweet Corn in Floyd County, IA?

In Floyd County, IA, plant Sweet Corn after the last frost (around May 1) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Floyd County, IA for Sweet Corn?

Floyd County sits in USDA Zone 5a. Sweet Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Sweet Corn grow in Floyd County's climate?

Yes — Sweet Corn grows well in Floyd County's temperate climate. Floyd County averages a 159-day frost-free season, with last frost around May 1 and first frost around October 7.

🌱

Your Floyd County Garden Planner — Free

A 22-page printable planner built for Floyd 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 Floyd County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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