Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when it's a good idea to plant radicchio by checking out the USDA zone info for California.

Planting Calendar for Radicchio

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

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

The earliest that you can plant radicchio in California is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant radicchio and expect a good harvest is probably September. If you wait any later than that and your radicchio may not have a chance to fully mature. If you are starting your radicchio indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In California the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for California may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in California there is a last frost after April 15 be ready to protect your radicchio if you have a late frost.

USDA Zone Info for California

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in California

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