One of the first steps you take when you are getting a good idea 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 figure out when you can plant larkspur by referring to the USDA zone info.

Planting Calendar for Larkspur

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

Since larkspur are very cold tolerant you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant larkspur 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 larkspur and expect a good harvest is probably October. If you wait any later than that and your larkspur may not have a chance to grow to maturity. You can get started a little bit earlier by starting your larkspur indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for San Francisco and it is different every year. Since half of the time in San Francisco you get surprised by a frost after January 31 be ready to cover your larkspur in the event of 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.