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.

In Costa Mesa you can figure out when it's the best time to plant radicchio by looking at the USDA zone info.

Planting Calendar for Radicchio

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

Radicchio do well in moderate cold which tells us that you can start planting them earlier than other frost tender plants.

The earliest that you can plant radicchio in Costa Mesa 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 radicchio and expect a good harvest is probably October. If you wait any later than that and your radicchio may not have a chance to really do well. You can get started a few weeks earlier by starting your radicchio indoors.

Last Frost Date

On average the last frost is on January 31 in Costa Mesa. In the coldest months of winter you should expect an average low temperature of 35°F.

It's important to remember that USDA zone info for Costa Mesa is an average and the actual date of last frost is different every year. Half of the time in Costa Mesa last frost occurs after January 31 so make sure that you are prepared to cover your radicchio in the event of a late frost.

USDA Zone Info for Costa Mesa

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 Costa Mesa

You may be interested in your other planting guides for Costa Mesa.