Before planting it is a good idea to find your USDA Zone info to estimate 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 figure out when to plant larkspur by looking at the USDA zone info for San Mateo.

Planting Calendar for Larkspur

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

Since larkspur do well in cold you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant larkspur in San Mateo 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 fully mature. You can get started a couple of weeks earlier by starting your larkspur indoors.

Last Frost Date

The average date of last frost is January 31 in San Mateo. In the coldest months of winter you should expect an average low temperature of 30°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for San Mateo and it is different every year. Since half of the time in San Mateo you get surprised by a frost after January 31 be ready to protect your larkspur in the event of a late frost.

USDA Zone Info for San Mateo

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Mateo

You may be interested in your other planting guides for San Mateo.