One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's possible to plant sweet potatos in Philadelphia by looking at the USDA zone info.

Planting Calendar for Sweet Potatos

Frost tolerance for sweet potatos:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since sweet potatos are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant sweet potatos in Philadelphia is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant sweet potatos and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet potatos may not have a chance to grow to maturity. Starting your sweet potatos indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Philadelphia. You can expect an average low temperature of 10°F in the coldest months of winter.

Remember that USDA zone info for Philadelphia is an average and the actual date of last frost will vary from year to year. Since half of the time in Philadelphia you get surprised by a frost after March 15 be ready to cover your sweet potatos if you have a late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Philadelphia

You may be interested in your other planting guides for Philadelphia.