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

A way of figuring out when it's the best time to plant black eyed susans is to consult the USDA zone info for San Ramon.

Planting Calendar for Black Eyed Susans

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

It's probably not a good idea to plant black eyed susans until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant black eyed susans in San Ramon is March. However, you really should wait until April 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 fully mature. 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 is on February 15 in San Ramon. It might get as low as 25°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Ramon and it will vary from year to year. Since half of the time in San Ramon you get a frost after February 15 be ready to protect your black eyed susans in the event of one of those late frosts.

USDA Zone Info for San Ramon

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Ramon

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