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.

The earliest that you can plant leeks in Philadelphia can be determined by using 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.

Leeks can survive in quite a bit of cold which tells us that you can plant them a lot 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. Any later than that and 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 little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Philadelphia. It might get as low as 10°F during the coldest months of winter.

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 there is a last frost after March 15 be ready to cover your leeks 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.