One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

In San Francisco you can determine when you can plant pentas by reviewing the USDA zone info.

Planting Calendar for Pentas

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

Since pentas do not do well in cold weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant pentas 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 pentas and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pentas may not have a chance to fully mature. If you are starting your pentas 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.

Since the USDA zone info for San Francisco is not always accurate the actual date of last frost changes 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 pentas 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.