The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when to plant larkspur is to look at the USDA zone info for Los Altos.

Planting Calendar for Larkspur

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

You can plant larkspur quite a bit earlier in the year because they do well in cold.

The earliest that you can plant larkspur in Los Altos 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. 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

In Los Altos the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Los Altos is just an average the actual date of last frost changes from year to year. Half of the time in Los Altos last frost occurs after February 15 so be sure to be ready to cover your larkspur if you have one of those late frosts.

USDA Zone Info for Los Altos

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Los Altos

You may be interested in your other planting guides for Los Altos.