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When to Plant Corn in Morgan County, IL

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.

Morgan County, Illinois is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 1,348 feet, Morgan County receives approximately 39.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Corn during the growing season.

Morgan County, IL (Zone 5b) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Morgan County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 6
Recommended (50%) ✓ Fits season (67 days to spare)
Transplant: Apr 14 🍅 Harvest: Jun 16 – Aug 11
Safe Start (90%) ✓ Fits season (61 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Aug 28

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 233 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Corn needs ~1,160 GDD — county provides 2,697 GDD Excellent fit

Corn Planting Timeline โ€” Morgan County, IL

Corn Planting Calendar

Activity When Date Range
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest June 23 Jun 23 โ€“ Aug 18

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

186 days

Growing Tips for Morgan 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Corn in Morgan County, IL?

Morgan County is in Zone 5b with an average last frost of April 14. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Morgan County, IL?

Morgan County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Morgan County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Morgan County, IL. Local conditions may vary. Last updated: April 2026.