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When to Plant Sweet Potatoes in Ruby, VA

Stafford County, Virginia Zone 7a August

August in Stafford County, Virginia — your action list

A quick August briefing for Stafford County, Virginia gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 3
Avg. first frost November 4
Soil temp (4") 85°F
Watering Low
Pest pressure High
Daylight 13.5 hrs

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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.

Ruby, Virginia is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is November 4, giving you a growing season of approximately 215 days.

At an elevation of 537 feet, Stafford County receives approximately 47 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Sweet Potatoes during the growing season.

Ruby, VA (Zone 7a) Long season
215 days
Last Spring Frost April 3
215 growing days
First Fall Frost November 4

Ruby Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.9

Drainage

Well Drained

Sweet Potatoes Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Feb 5 Transplant: Apr 9 🍅 Harvest: Jul 9 – Aug 27
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Feb 13 Transplant: Apr 17 🍅 Harvest: Jul 17 – Sep 4
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Mar 19 Transplant: May 21 🍅 Harvest: Aug 20 – Oct 8

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 Ruby

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

Soil pH

Your soil pH (5.4–6.9) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

The silt loam soil in Stafford 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

Sweet Potatoes Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 157 gal / 100 sq ft

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 3.8" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 5.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 4.3" 3.5" 0.8" 💧 Light watering
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Stafford 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 ~1,838 GDD — county provides 3,762 GDD Excellent fit

Sweet Potatoes Planting Timeline — Ruby, VA

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 13 Feb 13 – Feb 27
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 10 Apr 10 – May 1
Harvest July 17 Jul 17 – Sep 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

215 days in Stafford County

Growing Tips for Sweet Potatoes in Ruby

Direct sow Sweet Potatoes outdoors after April 03 in Stafford County when soil has warmed and frost danger has passed.

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 →

🌱

Your Stafford County Garden Planner — Free

A 22-page printable planner built for Stafford County (Zone 7a). 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 Stafford County, VA. Local conditions may vary. Last updated: August 2026.