Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portland you can determine when you can plant bok choi by referring to the USDA zone info.

Planting Calendar for Bok Choi

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

Bok Choi are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant bok choi in Portland is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant bok choi and expect a good harvest is probably October. You probably don't want to wait any later than that or else your bok choi may not have a chance to really do well. Starting your bok choi indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Portland. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Portland is just an average the actual date of last frost changes from year to year. Since half of the time in Portland you get surprised by a frost after February 15 be ready to cover your bok choi in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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