One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

In Rio Vista you can figure out when you can plant larkspur by using 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 do well in cold you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant larkspur in Rio Vista 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 little bit earlier by starting your larkspur indoors.

Last Frost Date

The average date of last frost is February 15 in Rio Vista. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Rio Vista is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rio Vista it frosts late in the year after February 15 so be sure to be ready to protect your larkspur in the event of one of those late frosts.

USDA Zone Info for Rio Vista

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 Rio Vista

You may be interested in your other planting guides for Rio Vista.