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When to Plant Sweet Potatoes in Granville County, NC

Granville County, North Carolina Zone 8a May

What to do in May

Your garden in Granville County, North Carolina is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 2
Avg. first frost November 3
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Sow sweet potatoes in trays indoors

    These need a head start before your last frost (April 2). Sow into cells now so you're ready to transplant in a few weeks.

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Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Granville County, North Carolina is in USDA Zone 8a. The average last spring frost is April 2 and the first fall frost is November 3, giving you a growing season of approximately 215 days.

At an elevation of 1,102 feet, Granville County receives approximately 52.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Sweet Potatoes during the growing season. Clay soil retains moisture well for Sweet Potatoes, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Granville County, NC (Zone 8a) Long season
215 days
Last Spring Frost April 2
215 growing days
First Fall Frost November 3
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Granville County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🍅 Harvest: Jul 7 – Aug 25
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jul 16 – Sep 3
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: Mar 3 Transplant: May 5 🍅 Harvest: Aug 4 – Sep 22

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 Granville County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (5.7–6.2) is within Sweet Potatoes's preferred range (5.5–6.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Sweet Potatoes.

How to Plant Sweet Potatoes

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

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
Drought risk

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

Monthly Watering Guide for Sweet Potatoes

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

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan 5" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 3.6" 0.7" 💧 Light watering
Dec 4.2" 0" ❄️ Dormant

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

Sweet Potatoes 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.

Sweet Potatoes needs ~1,680 GDD — county provides 3,440 GDD Excellent fit

Sweet Potatoes Planting Timeline — Granville County, NC

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 – Feb 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 9 Apr 9 – Apr 30
Harvest July 16 Jul 16 – Sep 3

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

215 days in Granville County

Growing Tips for Sweet Potatoes in Granville County

Direct sow Sweet Potatoes outdoors after April 02 in Granville County when soil has warmed and frost danger has passed.

With Granville County's clay soil (28% clay), work in 3-4 inches of compost before planting Sweet Potatoes. Avoid tilling when soil is wet to prevent compaction.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Granville County, NC?

Granville County is in Zone 8a with an average last frost of April 2. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Granville County, NC?

Granville County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 2 and first fall frost is November 3.

🌱

Your Granville County Garden Planner — Free

A 24-page printable planner built for Granville 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 Granville 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.