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

The earliest that you can plant four o' clock in South San Francisco can be estimated by looking at the USDA zone info.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant four o' clock until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant four o' clock in South 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 four o' clock and expect a good harvest is probably September. Any later than that and your four o' clock may not have a chance to really do well. Starting your four o' clock indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in South San Francisco. You can expect an average low temperature of 30°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for South San Francisco and it can change quite a bit from year to year. Since half of the time in South San Francisco you get surprised by a frost after January 31 be ready to cover your four o' clock in the event of a surprise late frost.

USDA Zone Info for South San Francisco

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in South San Francisco

You may be interested in your other planting guides for South San Francisco.