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When to Plant Sweet Potatoes in Cambria County, PA

Cambria County, Pennsylvania Zone 6a May

Your May game plan for Cambria County, Pennsylvania

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

Avg. last frost May 9
Avg. first frost October 12
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Harden off and plant sweet potatoes

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Put sweet potatoes seeds straight in the ground

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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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.

Cambria County, Pennsylvania is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is October 12, giving you a growing season of approximately 156 days.

At an elevation of 720 feet, Cambria County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Sweet Potatoes during the growing season.

Cambria County, PA (Zone 6a) Moderate season
156 days
Last Spring Frost May 9
156 growing days
First Fall Frost October 12
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Cambria County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Mar 6 Transplant: May 15 🍅 Harvest: Aug 14 – Oct 2
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 14 Transplant: May 23 🍅 Harvest: Aug 22 – Oct 10
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: Mar 28 Transplant: Jun 6 🍅 Harvest: Sep 5 – Oct 24

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 Cambria County

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

Soil pH

Your soil pH (5.0–6.5) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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

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 2.9" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Cambria 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 ~1,916 GDD — county provides 2,847 GDD Excellent fit

Sweet Potatoes Planting Timeline — Cambria County, PA

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest August 22 Aug 22 – Oct 10

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6a

📆 Growing Season

156 days in Cambria County

Growing Tips for Sweet Potatoes in Cambria County

Direct sow Sweet Potatoes outdoors after May 09 in Cambria 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 →

Frequently Asked Questions

When should I plant Sweet Potatoes in Cambria County, PA?

Cambria County is in Zone 6a with an average last frost of May 9. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cambria County, PA?

Cambria County, Pennsylvania is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is October 12.

🌱

Your Cambria County Garden Planner — Free

A 24-page printable planner built for Cambria County (Zone 6a). 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 Cambria County, PA. 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.