One of the best tools that you have as gardeners to help us figure out 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.

A common way of figuring out when you can plant calibrachoa is to consult the USDA zone info for San Francisco.

Planting Calendar for Calibrachoa

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

Calibrachoa do well in mild cold which means that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant calibrachoa in San Francisco 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 calibrachoa and expect a good harvest is probably September. You probably don't want to wait any later than that or else your calibrachoa may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your calibrachoa indoors.

Last Frost Date

The average date of last frost is January 31 in San Francisco. You should expect an average low temperature of 35°F in the coldest months of winter.

Keep in mind that USDA zone info for San Francisco is not always accurate and the actual date of last frost changes from year to year. Since half of the time in San Francisco you get a frost after January 31 be ready to cover your calibrachoa if you have a surprise late frost.

USDA Zone Info for San Francisco

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Francisco

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