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.

You should be able to figure out when you can plant black radish by reviewing the USDA zone info for Sonoma.

Planting Calendar for Black radish

Frost tolerance for black radish:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant black radish a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant black radish in Sonoma is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant black radish and expect a good harvest is probably October. Any later than that and your black radish may not have a chance to fully mature. You can get started a few weeks earlier by starting your black radish indoors.

Last Frost Date

The average date of last frost is February 15 in Sonoma. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Sonoma is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Sonoma last frost occurs after February 15 so make sure that you are ready to protect your black radish in the event of 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.