One of the best tools that you have as gardeners to help us estimate 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.

A common way of estimating when it's possible to plant black eyed susans is to refer to the USDA zone info for San Diego.

Planting Calendar for Black Eyed Susans

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

You really shouldn't plant black eyed susans until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant black eyed susans in San Diego 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. You probably don't want to wait any later than that or else your black eyed susans may not have a chance to grow to maturity. Starting your black eyed susans indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on January 31 in San Diego. You can expect an average low temperature of 35°F in the coldest months of winter.

Since the USDA zone info for San Diego may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in San Diego you get surprised by a frost after January 31 be ready to protect your black eyed susans in the event of a late frost.

USDA Zone Info for San Diego

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 Diego

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