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When to Plant Collard Greens in Iredell County, NC

Iredell County, North Carolina Zone 7b May

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

Welcome to May in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 7
Avg. first frost November 1
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Start collard greens indoors

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Get ahead of June
  • First harvests: collard greens

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Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

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 Collard Greens during the growing season. Clay soil retains moisture well for Collard Greens, 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

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)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 20 – Jul 22
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jun 2 – Aug 4
Safe Start (90%) ✓ Fits season (88 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 16 – 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 Collard Greens's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Collard Greens.

How to Plant Collard Greens

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Collard Greens

4
successive plantings in your 208-day season

Sow every 6.3 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Collard Greens

Collard Greens needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Collard Greens Needs Rainfall You Supplement Action
Jan 4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 3.5" 3.3" 0.2" 💧 Light watering
May 3.5" 4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.2" 0" ✅ Rainfall sufficient
Jul 3.5" 4.1" 0" ✅ Rainfall sufficient
Aug 3.5" 4.4" 0" ✅ Rainfall sufficient
Sep 3.5" 3.9" 0" ✅ Rainfall sufficient
Oct 3.5" 2.7" 0.8" 💧 Light watering
Nov 3.5" 3.3" 0.2" 💧 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.

Collard Greens 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.

Collard Greens needs ~1,186 GDD — county provides 3,796 GDD Excellent fit

Collard Greens Planting Timeline — Iredell County, NC

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 24 Mar 24 – Apr 14
Harvest June 2 Jun 2 – Aug 4
Fall Sowing August 23 Aug 23 – Sep 6

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Fall Sowing Harvest
September Fall Sowing
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

208 days in Iredell County

Growing Tips for Collard Greens in Iredell County

Direct sow Collard Greens 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 Collard Greens. Avoid tilling when soil is wet to prevent compaction.

Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Iredell County, NC?

Iredell County is in Zone 7b with an average last frost of April 7. Plan your Collard Greens 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.

🌱

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.