When to Plant Corn in Marion County, MO
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.
Marion County, Missouri is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 21, giving you a growing season of approximately 190 days.
At an elevation of 1,252 feet, Marion County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Corn to ensure they mature before fall.
Marion County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.7
Drainage
Well Drained
How Much Corn to Grow
For a family of 4, plant approximately 60 corn plants in about 120 sq ft. In Marion County's 190-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 | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Marion County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Corn Planting Timeline — Marion County, MO
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | June 23 | Jun 23 – Aug 18 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
190 days in Marion County
Growing Tips for Marion 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
Check more plant combinations with our Companion Planting Checker →
Corn in Other Locations
Frequently Asked Questions
When should I plant Corn in Marion County, MO?
Marion County is in Zone 5b with an average last frost of April 14. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marion County, MO?
Marion County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 21.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Marion County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.