One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant verbena in San Francisco can be determined by reviewing the USDA zone info.

Planting Calendar for Verbena

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

Verbena are barely cold tolerant which tells us that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant verbena 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 verbena and expect a good harvest is probably September. You probably don't want to wait any later than that or else your verbena may not have a chance to grow to maturity. If you are starting your verbena indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on January 31 in San Francisco. It might get as low as 35°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Francisco and it changes from year to year. Half of the time in San Francisco last frost occurs after January 31 so make sure that you are ready to protect your verbena in the event of a 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.