Before planting it is a good idea to find your USDA Zone info to figure out 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 possible to figure out when to plant petunias by referring to the USDA zone info for South San Francisco.

Planting Calendar for Petunias

Frost tolerance for petunias:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Petunias tend to make it in mild cold which means that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant petunias in South San Francisco 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 petunias and expect a good harvest is probably September. You probably don't want to wait any later than that or else your petunias may not have a chance to really do well. Starting your petunias indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in South San Francisco. In the coldest months of winter you should expect an average low temperature of 30°F.

Always keep in mind that USDA zone info for South San Francisco is not always accurate and the actual date of last frost is different every year. Half of the time in South San Francisco you get a frost after January 31 so always be ready to cover your petunias if you have a late frost.

USDA Zone Info for South San Francisco

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 South San Francisco

You may be interested in your other planting guides for South San Francisco.