The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Colby you will be able to figure out when it's a good idea 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.

Radicchio do ok in mild cold which means that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant radicchio in Colby 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. If you wait any later than that and your radicchio may not have a chance to really do well. 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 Colby. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Colby may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Colby last frost occurs after April 15 so be sure to be ready to cover your radicchio in the event of a late frost.

USDA Zone Info for Colby

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 Colby

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