One of the first steps you take when you are getting a good idea 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.

By referring to the USDA zone info for Healdsburg you should be able to estimate when it's possible to plant radicchio.

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 bit earlier in the year than other frost tender plants.

The earliest that you can plant radicchio in Healdsburg 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. Any later than that and your radicchio may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your radicchio indoors.

Last Frost Date

The average date of last frost is February 15 in Healdsburg. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Healdsburg is an average the actual date of last frost is different every year. Half of the time in Healdsburg you get a frost after February 15 so make sure that you are prepared to protect your radicchio if you have a surprise late frost.

USDA Zone Info for Healdsburg

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 Healdsburg

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