One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In San Francisco you can estimate when it's the best time to plant pennyroyal by referring to the USDA zone info.

Planting Calendar for Pennyroyal

Frost tolerance for pennyroyal:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Pennyroyal do ok in quite a bit of cold which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant pennyroyal 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 pennyroyal and expect a good harvest is probably October. Any later than that and your pennyroyal may not have a chance to fully mature. You can get started a few weeks earlier by starting your pennyroyal indoors.

Last Frost Date

The average date of last frost is January 31 in San Francisco. In the coldest months of winter you can expect an average low temperature of 35°F.

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. Since half of the time in San Francisco there is a last frost after January 31 be ready to cover your pennyroyal 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.