One of the first steps you take when you are making a decision about 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 best time to plant purslane in San Francisco should be determined by using the USDA zone info.

Planting Calendar for Purslane

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

Purslane are barely cold tolerant which means that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant purslane 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 purslane and expect a good harvest is probably September. You probably don't want to wait any later than that or else your purslane may not have a chance to grow to maturity. Starting your purslane indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in San Francisco. It might get as low as 35°F during the coldest months of winter.

Keep in mind that USDA zone info for San Francisco is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in San Francisco last frost occurs after January 31 be ready to protect your purslane in the event of a late frost.

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.