One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In South San Francisco you can estimate when it's the best time to plant black eyed susans by referring to the USDA zone info.

Planting Calendar for Black Eyed Susans

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

Black Eyed Susans do not do well in cold weather which means that it is necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant black eyed susans 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 black eyed susans and expect a good harvest is probably September. Any later than that and your black eyed susans may not have a chance to grow to maturity. If you are starting your black eyed susans indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in South San Francisco. It might get as low as 30°F during 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 changes from year to year. Since half of the time in South San Francisco last frost occurs after January 31 be ready to cover your black eyed susans if you have a 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.