Blog

When to Plant Corn in Mississippi County, MO

Mississippi County, Missouri Zone 7b May

May in Mississippi County, Missouri — your action list

Your Mississippi County, Missouri garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 1
Avg. first frost October 28
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14 hrs
To set up a strong June, finish these tasks
  • First harvests: corn

Instant PDF download. No spam, unsubscribe any time.

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.

Mississippi County, Missouri is in USDA Zone 7b. The average last spring frost is April 1 and the first fall frost is October 28, giving you a growing season of approximately 210 days.

At an elevation of 1,274 feet, Mississippi County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Corn during the growing season.

Mississippi County, MO (Zone 7b) Long season
210 days
Last Spring Frost April 1
210 growing days
First Fall Frost October 28

Mississippi County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Transplant: Mar 26 🍅 Harvest: May 28 – Jul 23
Recommended (50%) ✓ Fits season (91 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 3 – Jul 29
Safe Start (90%) ✓ Fits season (85 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 19 – Aug 14

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 Mississippi County

How your county's soil matches Corn's growing requirements.

Soil pH

Your soil pH (5.6–6.6) overlaps with Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Mississippi County is excellent for Corn — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Corn.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Corn.

How to Plant Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Corn

4
successive plantings in your 210-day season

Sow every 6.9 weeks. Last sowing by Jul 20 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 467 gal / 100 sq ft

Monthly Watering Guide for Corn

Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Corn Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 6.5" 4.2" 2.3" 💧 Light watering
May 6.5" 4.7" 1.8" 💧 Light watering
Jun 6.5" 5.1" 1.4" 💧 Light watering
Jul 6.5" 4.3" 2.2" 💧 Light watering
Aug 6.5" 4.3" 2.2" 💧 Light watering
Sep 6.5" 3.7" 2.8" 💧 Light watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Corn Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Corn needs ~1,160 GDD — county provides 3,045 GDD Excellent fit

Corn Planting Timeline — Mississippi County, MO

Corn Planting Calendar

Activity When Date Range
Direct Sow April 8 Apr 8 – Apr 29
Harvest June 10 Jun 10 – Aug 5

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

210 days in Mississippi County

Growing Tips for Corn in Mississippi County

Direct sow Corn outdoors after April 01 in Mississippi 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

  • Tomatoes
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Mississippi County, MO?

Mississippi County is in Zone 7b with an average last frost of April 1. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mississippi County, MO?

Mississippi County, Missouri is in USDA Hardiness Zone 7b. The average last spring frost is April 1 and first fall frost is October 28.

🌱

Your Mississippi County Garden Planner — Free

A 24-page printable planner built for Mississippi County (Zone 7b). 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 Mississippi County, MO. Local conditions may vary. Last updated: May 2026.

Sources & credits

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