The USDA Zone info is a great tool for gardeners to help us estimate 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 determine when it's possible to plant tritoma in Philadelphia by looking at the USDA zone info.

Planting Calendar for Tritoma

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

You can plant tritoma earlier in the year because they are very cold tolerant.

The earliest that you can plant tritoma 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 tritoma and expect a good harvest is probably September. You probably don't want to wait any later than that or else your tritoma may not have a chance to really do well. If you are starting your tritoma indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Philadelphia. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Philadelphia is just an average the actual date of last frost will vary from year to year. Since half of the time in Philadelphia you get a frost after March 15 be ready to cover your tritoma 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.