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When to Plant Sunflower in Warren County, NC

Warren County, North Carolina Zone 7b May

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

May is a pivotal month for Warren County, North Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 9
Avg. first frost October 31
Soil temp (4") 68°F
Watering Moderate
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: sunflower

    These need a head start before your last frost (April 9). Sow into cells now so you're ready to transplant in a few weeks.

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Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Warren County, North Carolina is in USDA Zone 7b. The average last spring frost is April 9 and the first fall frost is October 31, giving you a growing season of approximately 205 days.

At an elevation of 485 feet, Warren County receives approximately 43.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Sunflower during the growing season. Clay soil retains moisture well for Sunflower, but amend with compost to improve drainage and prevent root rot.

Warren County, NC (Zone 7b) Long season
205 days
Last Spring Frost April 9
205 growing days
First Fall Frost October 31
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Warren County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Feb 9 Transplant: Apr 13 🍅 Harvest: Jun 22 – Aug 10
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jul 2 – Aug 20
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Mar 6 Transplant: May 8 🍅 Harvest: Jul 17 – Sep 4

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 Warren County

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

Soil pH

Your soil pH (5.3–6.2) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

3
successive plantings in your 205-day season

Sow every 8 weeks. Last sowing by Jul 23 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Sunflower

Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan 3.1" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 4.9" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2.6" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

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

Sunflower 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.

Sunflower needs ~1,360 GDD — county provides 3,280 GDD Excellent fit

Sunflower Planting Timeline — Warren County, NC

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 16 Apr 16 – May 7
Harvest July 2 Jul 2 – Aug 20

Plant 1" deep · 18" apart · Rows 30" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

205 days in Warren County

Growing Tips for Sunflower in Warren County

Direct sow Sunflower outdoors after April 09 in Warren County when soil has warmed and frost danger has passed.

With Warren County's clay soil (34% clay), work in 3-4 inches of compost before planting Sunflower. Avoid tilling when soil is wet to prevent compaction.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Warren County, NC?

Warren County is in Zone 7b with an average last frost of April 9. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, NC?

Warren County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 9 and first fall frost is October 31.

🌱

Your Warren County Garden Planner — Free

A 24-page printable planner built for Warren 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 Warren 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.