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.

The USDA zone info for Seattle can be reviewed 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 moderate cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant radicchio in Seattle 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 fully mature. You can get started a little bit earlier by starting your radicchio indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Seattle. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Seattle is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Seattle last frost occurs after March 15 so always be ready to protect your radicchio in the event of a surprise late frost.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Seattle

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