The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for San Francisco it's possible to estimate when you can plant violas.

Planting Calendar for Violas

Frost tolerance for violas:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant violas quite a bit earlier in the year because they do well in cold.

The earliest that you can plant violas in San Francisco 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 violas and expect a good harvest is probably October. If you wait any later than that and your violas may not have a chance to grow to maturity. You can get started a little bit earlier by starting your violas indoors.

Last Frost Date

In San Francisco the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 35°F.

Just be sure to remember that USDA zone info for San Francisco is an average and the actual date of last frost changes from year to year. Since half of the time in San Francisco there is a last frost after January 31 be ready to cover your violas 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.