When to Plant Sweet Potatoes in Carbon County, PA
Your May gardening checklist
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Carbon County, Pennsylvania.
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Transplant sweet potatoes outside
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Direct-sow sweet potatoes
Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.
June will be here before you know it — start on
- Starting indoors: sweet potatoes
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 6b. 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.
Soil Compatibility in Carbon County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (4.8–6.2) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Carbon County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.5%). Annual compost additions will help Sweet Potatoes.
How to Plant Sweet Potatoes
Plant Water Budget
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 | — | 2.8" | 0" | ❄️ Dormant |
| Feb | — | 2.9" | 0" | ❄️ Dormant |
| Mar | — | 3.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jul | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4" | 0.3" | 💧 Light watering |
| Sep | 4.3" | 4" | 0.3" | 💧 Light watering |
| Oct | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Nov | — | 3.6" | 0" | ❄️ Dormant |
| Dec | — | 3.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Carbon 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 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
1"/week · Natural rainfall sufficient
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
176 days in Carbon County
Growing Tips for Sweet Potatoes in Carbon County
Direct sow Sweet Potatoes outdoors after April 26 in Carbon 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
Check more plant combinations with our Companion Planting Checker →
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Carbon County, PA?
Carbon County is in Zone 6b 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 6b. The average last spring frost is April 26 and first fall frost is October 19.
Your Carbon County Garden Planner — Free
A 24-page printable planner built for Carbon County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.