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

In Napa you can figure out when it's the best time to plant perilla by referring to 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.

It's not a good idea to plant perilla until after all chance of frost has passed because they require warm weather.

The earliest that you can plant perilla in Napa is March. However, you really should wait until April 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. 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

On average the last frost is on February 15 in Napa. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Napa is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Napa it frosts late in the year after February 15 be ready to cover your perilla in the event of a surprise late frost.

USDA Zone Info for Napa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Napa

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