One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Sonoma it's a good idea to determine when you can plant black eyed susans.

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.

You can not plant black eyed susans until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant black eyed susans in Sonoma 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. You probably don't want to wait any later than that or else your black eyed susans may not have a chance to really do well. 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 February 15 in Sonoma. You should expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Sonoma and it will vary from year to year. Half of the time in Sonoma there is a last frost after February 15 so make sure that you are prepared to cover your black eyed susans if you have a surprise late frost.

USDA Zone Info for Sonoma

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 Sonoma

You may be interested in your other planting guides for Sonoma.