Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's the best time to plant radicchio is to use the USDA zone info for Lewiston.

Planting Calendar for Radicchio

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

Since radicchio do well in moderate cold you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant radicchio in Lewiston 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 couple of weeks earlier.

Last Frost Date

In Lewiston the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Lewiston is an average the actual date of last frost changes from year to year. Since half of the time in Lewiston there is a last frost after April 15 be ready to cover your radicchio in the event of one of those late frosts.

USDA Zone Info for Lewiston

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 Lewiston

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