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.

You should be able to estimate when it's a good idea to plant torenia by reviewing the USDA zone info for San Francisco.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant torenia until after the last frost has passed because they require warm weather.

The earliest that you can plant torenia 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 torenia and expect a good harvest is probably September. If you wait any later than that and your torenia may not have a chance to really do well. If you are starting your torenia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for San Francisco and it can change quite a bit from year to year. Since half of the time in San Francisco you get surprised by a frost after January 31 be ready to protect your torenia 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.