One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for San Jose can be reviewed to estimate when you can plant larkspur.

Planting Calendar for Larkspur

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

Larkspur do well in quite a bit of cold which means that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant larkspur in San Jose 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. You probably don't want to wait any later than that or else your larkspur may not have a chance to really do well. Starting your larkspur indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in San Jose. It might get as low as 25°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for San Jose and it will vary from year to year. Half of the time in San Jose it frosts late in the year after February 15 so make sure that you are ready to cover your larkspur if you have a late frost.

USDA Zone Info for San Jose

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 San Jose

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