Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for San Francisco it's possible to figure out when it's possible to plant skullcap.

Planting Calendar for Skullcap

Frost tolerance for skullcap:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's a bad idea to plant skullcap until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant skullcap 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 skullcap and expect a good harvest is probably September. You probably don't want to wait any later than that or else your skullcap may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your skullcap indoors.

Last Frost Date

On average the last frost is on 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 may not be accurate from year to year 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 skullcap if you have a surprise 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.