One of the best tools that you have as gardeners to help us figure out 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.

In Billings you can figure out when you can plant perilla by checking out the USDA zone info.

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 it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant perilla in Billings 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. If you are starting your perilla indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Billings. In the coldest months of winter you can expect an average low temperature of -25°F.

Always keep in mind that USDA zone info for Billings is just an average and the actual date of last frost is different every year. Half of the time in Billings you get surprised by a frost after May 15 so just be sure to be ready to cover your perilla if you have a surprise late frost.

USDA Zone Info for Billings

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 Billings

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