The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 estimate when you can plant black radish by looking at the USDA zone info for San Luis.

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 one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant black radish in San Luis 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. You can get started a little bit earlier by starting your black radish indoors.

Last Frost Date

On average the last frost is on January 31 in San Luis. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for San Luis 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 Luis it frosts late in the year after January 31 be ready to cover your black radish in the event of a late frost.

USDA Zone Info for San Luis

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Luis

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