The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's a good idea to plant radicchio in Flagstaff by referring to the USDA zone info.

Planting Calendar for Radicchio

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

You can plant radicchio a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant radicchio in Flagstaff 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. You probably don't want to wait any later than that or else your radicchio may not have a chance to really do well. If you are starting your radicchio indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Flagstaff the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Flagstaff is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Flagstaff there is a last frost after April 15 so just be sure to be ready to cover your radicchio if you have a late frost.

USDA Zone Info for Flagstaff

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Flagstaff

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