One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's possible to plant perilla by checking out the USDA zone info for Zone 4b.

Planting Calendar for Perilla

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

You can not plant perilla until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant perilla in Zone 4b is May. However, you really should wait until June 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. You can get started a couple of weeks earlier by starting your perilla indoors.

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 4b and it changes from year to year. Since half of the time in Zone 4b there is a last frost after May 15 be ready to protect your perilla in the event of a surprise late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.