The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's possible to plant flax in Philadelphia by reviewing the USDA zone info.

Planting Calendar for Flax

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

Flax can survive in mild cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant flax 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 flax and expect a good harvest is probably September. You probably don't want to wait any later than that or else your flax may not have a chance to fully mature. Starting your flax indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Philadelphia. You can expect an average low temperature of 10°F in the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Philadelphia and it can change quite a bit from year to year. Half of the time in Philadelphia there is a last frost after March 15 so just be sure to be ready to cover your flax if you have 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.