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

One way of estimating when it's possible to plant radicchio is to look at the USDA zone info for Caribou.

Planting Calendar for Radicchio

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

Radicchio are one of those plants that can tolerate a little bit of cold weather which means that you can get them planted earlier than plants that are more sensitive to the cold.

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

The last month that you can plant radicchio and expect a good harvest is probably August. You probably don't want to wait any later than that or else your radicchio may not have a chance to really do well. 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 May 15 in Caribou. You should expect an average low temperature of -30°F in the coldest months of winter.

Remember that USDA zone info for Caribou is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Caribou it frosts late in the year after May 15 so always be ready to cover your radicchio in the event of a late frost.

USDA Zone Info for Caribou

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

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

Plants to Grow in Caribou

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