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When to Plant Corn in Iredell County, NC

Iredell County, North Carolina Zone 7b May

Iredell County, North Carolina gardeners: here's your May plan

Here's what deserves your attention in Iredell County, North Carolina this month. Everything below is tailored to Zone 7b and timed around your local frost dates.

Avg. last frost April 7
Avg. first frost November 1
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
Looking ahead to June
  • First harvests: corn

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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.

Iredell County, North Carolina is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is November 1, giving you a growing season of approximately 208 days.

At an elevation of 400 feet, Iredell County receives approximately 44.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, providing good warmth for Corn during the growing season. Clay soil retains moisture well for Corn, but amend with compost to improve drainage and prevent root rot.

Iredell County, NC (Zone 7b) Long season
208 days
Last Spring Frost April 7
208 growing days
First Fall Frost November 1
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Iredell County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (94 days to spare)
Transplant: Mar 25 🍅 Harvest: May 27 – Jul 22
Recommended (50%) ✓ Fits season (89 days to spare)
Transplant: Apr 7 🍅 Harvest: Jun 9 – Aug 4
Safe Start (90%) ✓ Fits season (88 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 23 – Aug 18

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 Iredell County

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

Soil pH

Your soil pH (5.5–6.7) overlaps with Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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 208-day season

Sow every 6.9 weeks. Last sowing by Jul 24 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,318 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 6.5" 3.3" 3.2" 💧 Light watering
May 6.5" 4" 2.5" 💧 Light watering
Jun 6.5" 4.2" 2.3" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 4.4" 2.1" 💧 Light watering
Sep 6.5" 3.9" 2.6" 💧 Light watering
Oct 6.5" 2.7" 3.8" 🚿 Regular watering
Nov 6.5" 3.3" 3.2" 💧 Light watering
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Iredell 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 ~1,460 GDD — county provides 3,796 GDD Excellent fit

Corn Planting Timeline — Iredell County, NC

Corn Planting Calendar

Activity When Date Range
Direct Sow April 14 Apr 14 – May 5
Harvest June 16 Jun 16 – Aug 11

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

208 days in Iredell County

Growing Tips for Corn in Iredell County

Direct sow Corn outdoors after April 07 in Iredell County when soil has warmed and frost danger has passed.

With Iredell County's clay soil (30% clay), work in 3-4 inches of compost before planting Corn. Avoid tilling when soil is wet to prevent compaction.

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 Iredell County, NC?

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

What planting zone is Iredell County, NC?

Iredell County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is November 1.

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Your Iredell County Garden Planner — Free

A 24-page printable planner built for Iredell 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.

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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 Iredell County, NC. 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.