One of the first steps you take when you are figuring out your gardening schedule is find your 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.

You can estimate when to plant radicchio in Atherton by reviewing 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 tend to make it in mild cold which tells us that 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 radicchio in Atherton 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. You probably don't want to wait any later than that or else your radicchio may not have a chance to fully mature. Starting your radicchio indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Atherton. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Atherton is an average and the actual date of last frost changes from year to year. Half of the time in Atherton there is a last frost after February 15 so just be sure to be ready to protect your radicchio if you have a surprise late frost.

USDA Zone Info for Atherton

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Atherton

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