The USDA Zone info is a great tool for gardeners to help us figure out 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.

The USDA zone info for Oregon should be reviewed to estimate when it's the best time to plant bok choi.

Planting Calendar for Bok Choi

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

You can plant bok choi a little earlier in the year because they do well in moderate cold.

The earliest that you can plant bok choi in Oregon 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 bok choi and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bok choi may not have a chance to grow to maturity. 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 April 15 in Oregon. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Oregon and it changes from year to year. Half of the time in Oregon you get surprised by a frost after April 15 so be sure to be ready to cover your bok choi if you have a surprise late frost.

USDA Zone Info for Oregon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oregon

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