The USDA Zone info is a great tool for gardeners to help us figure out 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.

A common way of figuring out when it's a good idea to plant perilla is to refer to the USDA zone info for Philadelphia.

Planting Calendar for Perilla

Frost tolerance for perilla:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Perilla do not do well in cold weather which means that you need to wait until it warms up after the last frost before you can plant them.

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

The last month that you can plant perilla and expect a good harvest is probably August. If you wait any later than that and your perilla may not have a chance to grow to maturity. If you are starting your perilla indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Philadelphia. You can expect an average low temperature of 0°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Philadelphia is just an average and the actual date of last frost will vary from year to year. Half of the time in Philadelphia last frost occurs after April 15 so be sure to be ready to cover your perilla if you have 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.