Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when you can plant browallia by looking at the USDA zone info for Napa.

Planting Calendar for Browallia

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

Since browallia are not cold tolerant it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant browallia 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 browallia and expect a good harvest is probably September. Any later than that and your browallia may not have a chance to really do well. Starting your browallia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Napa. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Napa is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Napa you get a frost after February 15 be ready to cover your browallia if you have a 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.