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When to Plant Cauliflower in Harnett County, NC

Harnett County, North Carolina Zone 8a May

Your May planting checklist for Harnett County, North Carolina

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

Avg. last frost March 29
Avg. first frost November 6
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Get cauliflower seeds going inside

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

  2. Collect cauliflower at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

June will be here before you know it — start on
  • First harvests: cauliflower

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Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

Harnett County, North Carolina is in USDA Zone 8a. The average last spring frost is March 29 and the first fall frost is November 6, giving you a growing season of approximately 222 days.

At an elevation of 613 feet, Harnett County receives approximately 53.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Cauliflower during the growing season. Clay soil retains moisture well for Cauliflower, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cauliflower root diseases.

Harnett County, NC (Zone 8a) Long season
222 days
Last Spring Frost March 29
222 growing days
First Fall Frost November 6
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Harnett County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Feb 16 Transplant: Mar 23 🍅 Harvest: May 18 – Jul 20
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 24 – Jul 26
Safe Start (90%) ✓ Fits season (95 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 12 – 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 Harnett County

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

Soil pH

Your soil pH (5.5–6.6) overlaps with Cauliflower's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cauliflower.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Cauliflower.

How to Plant Cauliflower

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 Cauliflower

4
successive plantings in your 222-day season

Sow every 6.3 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Cauliflower

Cauliflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cauliflower Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.3" 5" 0" ✅ Rainfall sufficient
Apr 4.3" 4.6" 0" ✅ Rainfall sufficient
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 4.3" 4.4" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

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

Cauliflower 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.

Cauliflower needs ~1,240 GDD — county provides 3,552 GDD Excellent fit

Cauliflower Planting Timeline — Harnett County, NC

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors March 29 Mar 29 – Apr 12
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 24 May 24 – Jul 26
Fall Sowing August 28 Aug 28 – Sep 11

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

55–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

222 days in Harnett County

Growing Tips for Cauliflower in Harnett County

Direct sow Cauliflower outdoors after March 29 in Harnett County when soil has warmed and frost danger has passed.

With Harnett County's clay soil (27% clay), work in 3-4 inches of compost before planting Cauliflower. Avoid tilling when soil is wet to prevent compaction.

Common pests for Cauliflower 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 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cauliflower in Harnett County, NC?

Harnett County is in Zone 8a with an average last frost of March 29. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harnett County, NC?

Harnett County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 29 and first fall frost is November 6.

🌱

Your Harnett County Garden Planner — Free

A 24-page printable planner built for Harnett County (Zone 8a). 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 Harnett 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.