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.

The best time to plant leeks in Philadelphia can be determined by checking out the USDA zone info.

Planting Calendar for Leeks

Frost tolerance for leeks:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since leeks are very cold tolerant you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant leeks 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 leeks and expect a good harvest is probably September. You probably don't want to wait any later than that or else your leeks may not have a chance to grow to maturity. If you are starting your leeks indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Philadelphia the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Keep in mind 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 it frosts late in the year after April 15 be ready to cover your leeks 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.