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.

It's a good idea to estimate when it's a good idea to plant delphinium by referring to the USDA zone info for San Pablo.

Planting Calendar for Delphinium

Frost tolerance for delphinium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since delphinium are barely cold tolerant you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in San Pablo is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant delphinium and expect a good harvest is probably September. Any later than that and your delphinium may not have a chance to really do well. Starting your delphinium indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in San Pablo. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for San Pablo may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in San Pablo you get surprised by a frost after January 31 be ready to protect your delphinium in the event of a late frost.

USDA Zone Info for San Pablo

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 Pablo

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