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When to plant Corn in Henry County, IA

Henry County gardeners should plant Corn between April 28 and May 19 in spring. With Henry County's Zone 5b climate (last frost April 21), Corn needs 60–100 days to mature — plant by July 6 for a full harvest.

When to Plant Corn in Henry County, IA

Corn

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Henry County, Iowa is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 14, giving you a growing season of approximately 176 days.

At an elevation of 879 feet, Henry County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Corn during the growing season.

Henry County, IA (Zone 5b) Moderate season
176 days
Last Spring Frost April 21
176 growing days
First Fall Frost October 14

Henry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

How Much Corn to Grow

1-2 ears
Average yield per plant
15
Plants per person
30 sq ft
Space per person

For a family of 4, plant approximately 60 corn plants in about 120 sq ft. In Henry County's 176-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Corn

Corn needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Corn Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 4.4" 0" ✅ Rainfall sufficient
May 4.3" 4.9" 0" ✅ Rainfall sufficient
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 4" 0.3" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Corn Planting Timeline — Henry County, IA

Corn Planting Calendar

Activity When Date Range
Direct Sow April 28 Apr 28 – May 19
Harvest June 30 Jun 30 – Aug 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

176 days in Henry County

Growing Tips for Henry County

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Henry County, IA?

Henry County is in Zone 5b with an average last frost of April 21. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henry County, IA?

Henry County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 14.

When should I plant Corn in Henry County, IA?

In Henry County, IA, plant Corn after the last frost (around April 21) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Henry County, IA for Corn?

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

Can Corn grow in Henry County's climate?

Yes — Corn grows well in Henry County's temperate climate. Henry County averages a 176-day frost-free season, with last frost around April 21 and first frost around October 14.

🌱

Your Henry County Garden Planner — Free

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

Sources & credits

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