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.

By using the USDA zone info for Johnston it's possible 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 when the weather gets warmer.

Perilla are not cold tolerant which means that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant perilla in Johnston 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 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

On average all chance of frost has passed is on April 15 in Johnston. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Johnston may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Johnston last frost occurs after April 15 be ready to cover your perilla in the event of a late frost.

USDA Zone Info for Johnston

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Johnston

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