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.

A common way of determining when it's possible to plant radicchio is to examine the USDA zone info for Calistoga.

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 a little bit of cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant radicchio in Calistoga 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 few weeks earlier by starting your radicchio indoors.

Last Frost Date

The average date of last frost is February 15 in Calistoga. In the coldest months of winter you should expect an average low temperature of 20°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Calistoga and it can change quite a bit from year to year. Since half of the time in Calistoga you get a frost after February 15 be ready to cover your radicchio if you have a late frost.

USDA Zone Info for Calistoga

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Calistoga

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