Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of making a decision about when it's a good idea to plant lettuce is to examine the USDA zone info for Philadelphia.

Planting Calendar for Lettuce

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

You can plant lettuce just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant lettuce 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 lettuce and expect a good harvest is probably September. Any later than that and your lettuce may not have a chance to grow to maturity. If you are starting your lettuce indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Philadelphia. In the coldest months of winter you can expect an average low temperature of 10°F.

Always keep in mind that USDA zone info for Philadelphia is not always accurate and the actual date of last frost is different every year. Since half of the time in Philadelphia you get surprised by a frost after March 15 be ready to cover your lettuce in the event of one of those late frosts.

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.