One of the first steps you take when you are determining your gardening schedule is find your 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 Petaluma can be read to estimate when it's possible to plant browallia.

Planting Calendar for Browallia

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

It's probably not a good idea to plant browallia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant browallia in Petaluma 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. You probably don't want to wait any later than that or else your browallia may not have a chance to really do well. If you are starting your browallia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Petaluma the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Petaluma and it is different every year. Half of the time in Petaluma you get a frost after February 15 so just be sure to be ready to cover your browallia if you have a late frost.

USDA Zone Info for Petaluma

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 Petaluma

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