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.

The first opportunity to plant black radish in San Diego should be estimated by looking at 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.

You can plant black radish a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

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 really do well. If you are starting your black radish 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 has passed is on February 15 in San Diego. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for San Diego is just an average the actual date of last frost is different every year. Half of the time in San Diego it frosts late in the year after February 15 so make sure that you are prepared 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 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

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