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When to Plant Corn in Dunklin 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.

Dunklin County, Missouri is in USDA Zone 7a. The average last spring frost is March 27 and the first fall frost is November 2, giving you a growing season of approximately 220 days.

At an elevation of 1,344 feet, Dunklin County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94ยฐF, providing good warmth for Corn during the growing season.

Dunklin County, MO (Zone 7a) Long season
220 days
Last Spring Frost March 27
220 growing days
First Fall Frost November 2

Dunklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Transplant: Mar 19 🍅 Harvest: May 21 – Jul 16
Recommended (50%) ✓ Fits season (101 days to spare)
Transplant: Mar 27 🍅 Harvest: May 29 – Jul 24
Safe Start (90%) ✓ Fits season (101 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 18 – Aug 13

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 Dunklin County

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

Soil pH

Your soil pH (5.6โ€“7.1) overlaps with Corn's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Dunklin County is excellent for Corn โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). 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 220-day season

Sow every 6.9 weeks. Last sowing by Jul 25 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,685 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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar 6.5" 2.4" 4.1" ๐Ÿšฟ Regular watering
Apr 6.5" 2.8" 3.7" ๐Ÿšฟ Regular watering
May 6.5" 4.1" 2.4" ๐Ÿ’ง Light watering
Jun 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
Jul 6.5" 3.7" 2.8" ๐Ÿ’ง Light watering
Aug 6.5" 3.5" 3" ๐Ÿ’ง Light watering
Sep 6.5" 3.2" 3.3" ๐Ÿšฟ Regular watering
Oct 6.5" 2.8" 3.7" ๐Ÿšฟ Regular watering
Nov 6.5" 2.4" 4.1" ๐Ÿšฟ Regular watering
Dec โ€” 1.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Dunklin County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,640 GDD — county provides 4,510 GDD Excellent fit

Corn Planting Timeline โ€” Dunklin County, MO

Corn Planting Calendar

Activity When Date Range
Direct Sow April 3 Apr 3 โ€“ Apr 24
Harvest June 5 Jun 5 โ€“ Jul 31

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 โ€”
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

220 days in Dunklin County

Growing Tips for Corn in Dunklin County

Direct sow Corn outdoors after March 27 in Dunklin 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 Dunklin County, MO?

Dunklin County is in Zone 7a with an average last frost of March 27. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dunklin County, MO?

Dunklin County, Missouri is in USDA Hardiness Zone 7a. The average last spring frost is March 27 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dunklin County gardeners in Zone 7a 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.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Dunklin County, MO. Local conditions may vary. Last updated: April 2026.