When to Plant Sweet Potatoes in Carbon County, PA
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.
Carbon County, Pennsylvania is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 19, giving you a growing season of approximately 176 days.
At an elevation of 1,110 feet, Carbon County receives approximately 44.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sweet Potatoes to ensure they mature before fall.
Carbon County Soil Profile
Soil Type
Silt Loam
Soil pH
4.8-6.2
Drainage
Well Drained
Plant Planting Risk Windows
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.
Plant Water Budget
Sweet Potatoes Planting Timeline — Carbon County, PA
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | May 3 | May 3 – May 24 |
| Harvest | August 9 | Aug 9 – Sep 27 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
5.5 – 6.5
USDA Zone
Zone 5b
Growing Season
176 days
Growing Tips for Carbon County
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
Level Up Your Garden
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Carbon County, PA?
Carbon County is in Zone 5b with an average last frost of April 26. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Carbon County, PA?
Carbon County, Pennsylvania is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 19.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Carbon County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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