Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to estimate when it's possible to plant basil by referring to the USDA zone info for San Francisco.

Planting Calendar for Basil

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

Since basil require warm weather it's important to wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

On average all chance of frost has passed is on January 31 in San Francisco. It might get as low as 35°F during the coldest months of winter.

Just be sure to remember that USDA zone info for San Francisco is an average and the actual date of last frost is different every year. Half of the time in San Francisco you get a frost after January 31 so make sure that you are prepared to cover your basil in the event of 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.