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 possible to plant perilla is to refer to the USDA zone info for Watertown.

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 all chance of frost has passed before you can plant them.

The earliest that you can plant perilla in Watertown 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. You probably don't want to wait any later than that or else your perilla may not have a chance to fully mature. If you are starting your perilla indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Watertown the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Watertown is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Watertown it frosts late in the year after May 15 be ready to protect your perilla if you have a late frost.

USDA Zone Info for Watertown

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 Watertown

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