One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant black radish in San Diego should be figured out by referring to the USDA zone info.

Planting Calendar for Black radish

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

Since black radish are moderately cold tolerant you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant black radish in San Diego 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. If you wait any later than that and your black radish may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your black radish indoors.

Last Frost Date

On average the last frost has passed is on January 31 in San Diego. It might get as low as 35°F during 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 there is a last frost after January 31 be ready to cover your black radish if you have a surprise 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.