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

One way of getting a good idea when it's a good idea to plant perilla is to examine the USDA zone info for Rialto.

Planting Calendar for Perilla

Frost tolerance for perilla:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since perilla are not cold tolerant it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant perilla in Rialto is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant perilla and expect a good harvest is probably September. If you wait any later than that and your perilla may not have a chance to really do well. Starting your perilla indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in Rialto. It might get as low as 30°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Rialto and it changes from year to year. Half of the time in Rialto last frost occurs after January 31 so make sure that you are ready to cover your perilla if you have one of those late frosts.

USDA Zone Info for Rialto

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Rialto

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