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 figuring out when it's a good idea to plant radicchio is to look at the USDA zone info for Aspen.

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 means that you can start planting them earlier than other plants that might not handle the cold.

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

The last month that you can plant radicchio and expect a good harvest is probably September. Any later than that and your radicchio may not have a chance to fully mature. Starting your radicchio indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Aspen. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Aspen is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Aspen you get surprised by a frost after April 15 so make sure that you are ready to protect your radicchio in the event of a late frost.

USDA Zone Info for Aspen

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Aspen

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