Before planting it is a good idea to find your USDA Zone info to determine 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.

The USDA zone info for San Francisco can be reffered to in order to figure out when to plant bishop's weed.

Planting Calendar for Bishop's Weed

Frost tolerance for bishop's weed:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since bishop's weed are very cold tolerant you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant bishop's weed in San Francisco is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant bishop's weed and expect a good harvest is probably October. Any later than that and your bishop's weed may not have a chance to grow to maturity. If you are starting your bishop's weed indoors then you might be able to get away with starting them a couple of weeks 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.

Keep in mind that USDA zone info for San Francisco is not always accurate and the actual date of last frost changes from year to year. Half of the time in San Francisco you get a frost after January 31 so be sure to be ready to protect your bishop's weed 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.