The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when you can plant bee balm by checking out the USDA zone info for Philadelphia.

Planting Calendar for Bee Balm

Frost tolerance for bee balm:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since bee balm are barely cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bee balm in Philadelphia is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant bee balm and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bee balm may not have a chance to grow to maturity. If you are starting your bee balm 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 April 15 in Philadelphia. You should expect an average low temperature of 0°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Philadelphia and it can change quite a bit from year to year. Since half of the time in Philadelphia you get a frost after April 15 be ready to cover your bee balm in the event of a 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.