Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Portsmouth can be used to figure out when you can plant perilla.

Planting Calendar for Perilla

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

Since perilla are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant perilla in Portsmouth 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 fully mature. You can get started a little bit earlier by starting your perilla indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Portsmouth and it will vary from year to year. Since half of the time in Portsmouth there is a last frost after April 15 be ready to cover your perilla in the event of a surprise late frost.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Portsmouth

You may be interested in your other planting guides for Portsmouth.