Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Philadelphia you can figure out when it's possible to plant sweet peas by checking out the USDA zone info.

Planting Calendar for Sweet Peas

Frost tolerance for sweet peas:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Sweet Peas are barely cold tolerant which tells us that you can get them planted just a bit earlier than other frost tender plants.

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

The last month that you can plant sweet peas and expect a good harvest is probably August. If you wait any later than that and your sweet peas may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your sweet peas indoors.

Last Frost Date

The average date of last frost is April 15 in Philadelphia. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Philadelphia is not always accurate and the actual date of last frost changes from year to year. Half of the time in Philadelphia last frost occurs after April 15 so always be ready to protect your sweet peas if you have a late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Philadelphia

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