The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Philadelphia it's possible to estimate when to plant sorrel.

Planting Calendar for Sorrel

Frost tolerance for sorrel:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant sorrel just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

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

The last month that you can plant sorrel and expect a good harvest is probably September. You probably don't want to wait any later than that or else your sorrel may not have a chance to really do well. You can get started a couple of weeks earlier by starting your sorrel 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.

Since the USDA zone info for Philadelphia is not always accurate the actual date of last frost is different every year. Half of the time in Philadelphia last frost occurs after April 15 so make sure that you are prepared to cover your sorrel in the event of a surprise 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.