One of the first steps you take when you are making a decision about 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.

The USDA zone info for South San Francisco can be used to estimate when to plant celosia.

Planting Calendar for Celosia

Frost tolerance for celosia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You should not plant celosia until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant celosia 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 celosia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your celosia may not have a chance to fully mature. If you are starting your celosia 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 South San Francisco. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for South San Francisco is an average the actual date of last frost will vary from year to year. Since half of the time in South San Francisco last frost occurs after January 31 be ready to protect your celosia 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.