One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when it's the best time to plant bok choi is to consult the USDA zone info for Winters.

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 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 bok choi in Winters 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 fully mature. If you are starting your bok choi indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Winters and it is different every year. Half of the time in Winters there is a last frost after February 15 so just be sure to be ready to cover your bok choi if you have one of those late frosts.

USDA Zone Info for Winters

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 Winters

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