When to Plant Corn in Madison County, IA
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.
Madison County, Iowa is in USDA Zone 5a. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.
At an elevation of 1,022 feet, Madison County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Corn to ensure they mature before fall.
Madison County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-6.9
Drainage
Well Drained
Plant Planting Risk Windows
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 Madison County
How your county's soil matches Corn's growing requirements.
Soil pH
Your soil pH (6.3–6.9) is within Corn's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Madison County is excellent for Corn — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Corn will thrive.
How to Plant Corn
Succession Planting Corn
Sow every 6.9 weeks. Last sowing by Jul 03 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Corn Planting Timeline — Madison County, IA
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 1 | May 1 – May 22 |
| Harvest | July 3 | Jul 3 – Aug 28 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
1.5"/week · 1-2 times/week
📅 Days to Maturity
60–100 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
170 days in Madison County
Growing Tips for Corn in Madison County
Direct sow Corn outdoors after April 24 in Madison County when soil has warmed and frost danger has passed.
Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.
General growing tips
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
Level Up Your Garden
Corn in Other Locations
Frequently Asked Questions
When should I plant Corn in Madison County, IA?
Madison County is in Zone 5a with an average last frost of April 24. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Madison County, IA?
Madison County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 24 and first fall frost is October 11.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Madison County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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