The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for San Francisco you will be able to determine when you can plant trailing portulaca.

Planting Calendar for Trailing Portulaca

Frost tolerance for trailing portulaca:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since trailing portulaca do not do well in cold weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant trailing portulaca in 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 trailing portulaca and expect a good harvest is probably September. Any later than that and your trailing portulaca may not have a chance to really do well. If you are starting your trailing portulaca indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in San Francisco. You should expect an average low temperature of 35°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for San Francisco and it can change quite a bit from year to year. Half of the time in San Francisco last frost occurs after January 31 so just be sure to be ready to protect your trailing portulaca if you have one of those late frosts.

USDA Zone Info for San Francisco

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Francisco

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