One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 Prospect Heights can be looked at to determine when you can plant perilla.

Planting Calendar for Perilla

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

Since perilla require warm weather you must wait until after the last frost before you can plant them.

The earliest that you can plant perilla in Prospect Heights 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. Any later than that and your perilla may not have a chance to really do well. 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

In Prospect Heights the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

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 Prospect Heights and it will vary from year to year. Half of the time in Prospect Heights you get a frost after April 15 so be sure to be ready to cover your perilla if you have a surprise late frost.

USDA Zone Info for Prospect Heights

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Prospect Heights

You may be interested in your other planting guides for Prospect Heights.