Root Vegetable

When to Plant Sweet Potatoes in Pennsylvania

Not related to regular potatoes at all. Sweet potatoes need heat and a long growing season but reward with incredible harvests.

The Short Answer

Sweet potatoes in Pennsylvania are achievable but challenging — the season is just barely long enough for 90-day varieties in the southern half of the state. Southeastern Pennsylvania's Zone 7a conditions provide the best chance for success.

Pennsylvania Frost Dates

Your planting dates depend on which part of Pennsylvania you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Pennsylvania 5a, 5b, 6a May 5 - May 20 Sep 20 - Oct 5
Central Pennsylvania 5b, 6a, 6b Apr 25 - May 10 Oct 1 - Oct 15
Philadelphia Region 7a, 7b Apr 5 - Apr 20 Oct 15 - Nov 5

Sweet Potatoes Planting Schedule for Pennsylvania

Northern Pennsylvania (Zones 5a, 5b, 6a)

Average last frost: May 5 - May 20 · Average first frost: Sep 20 - Oct 5

Start Seeds Indoors
8 wks before frost
Transplant Outside
3 wks after frost

Central Pennsylvania (Zones 5b, 6a, 6b)

Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15

Start Seeds Indoors
8 wks before frost
Transplant Outside
3 wks after frost

Philadelphia Region (Zones 7a, 7b)

Average last frost: Apr 5 - Apr 20 · Average first frost: Oct 15 - Nov 5

Start Seeds Indoors
8 wks before frost
Transplant Outside
3 wks after frost

Growing Sweet Potatoes in Pennsylvania

State-Specific Growing Tips

Plant slips in late May to early June when soil reaches 65°F. Black plastic mulch is essential for warming Pennsylvania's soils. Raised beds over clay improve drainage and soil temperature. Choose 90-day varieties only. Harvest before first frost — critical in PA where frost arrives as early as October 1 in central counties. Cure at 80-85°F for 10 days.

Recommended Varieties for Pennsylvania

Beauregard (90 days) is the only reliable choice for Pennsylvania. Bush Porto Rico for small spaces. Penn State Extension considers sweet potatoes experimental in most of the state.

Common Challenges in Pennsylvania

Season length is marginal. Cool nights slow growth. Early frost catches unharvested tubers. Clay soils must be heavily amended. Success is most likely in southeastern PA.

Growing Tips

Grow from slips, not seeds. Start slips from a sweet potato in water 8 weeks before transplanting. Cure harvested tubers in warmth for 10 days.

Companion Planting

Plant sweet potatoes alongside these companions for better growth:

Beans Corn

Keep sweet potatoes away from:

Squash

The Bottom Line

Sweet Potatoes can be grown successfully in Pennsylvania with proper attention to regional frost dates and local growing conditions. Timing varies across the state — Northern Pennsylvania gardeners work with a last frost around May 5 - May 20, while Philadelphia Region sees frost end around Apr 5 - Apr 20. Choose varieties suited to your region, amend your soil based on its specific needs, and monitor for the pests and diseases most common in your area. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Sweet Potatoes Growing Guide National planting guide with all states Pennsylvania Planting Calendar All plants for Pennsylvania Sweet Potatoes in Alabama Alabama planting dates Sweet Potatoes in Alaska Alaska planting dates Sweet Potatoes in Arizona Arizona planting dates Sweet Potatoes in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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