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.

The USDA zone info for Ottumwa should be read to estimate 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 it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant perilla in Ottumwa 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. You probably don't want to wait any later than that or else your perilla may not have a chance to really do well. You can get started a few weeks earlier by starting your perilla indoors.

Last Frost Date

The average date of last frost is April 15 in Ottumwa. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Ottumwa is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Ottumwa you get a frost after April 15 so be sure to be ready to cover your perilla if you have a late frost.

USDA Zone Info for Ottumwa

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 Ottumwa

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