The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant salpiglossis in San Francisco should be figured out by looking at the USDA zone info.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably not a good idea to plant salpiglossis until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant salpiglossis 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 salpiglossis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your salpiglossis may not have a chance to fully mature. Starting your salpiglossis indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

It's important to remember 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 will vary from year to year. Since half of the time in San Francisco it frosts late in the year after January 31 be ready to cover your salpiglossis in the event of 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.