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.

You should be able to estimate when to plant bok choi by reviewing the USDA zone info for Zone 9a.

Planting Calendar for Bok Choi

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

Since bok choi are moderately cold tolerant you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant bok choi in Zone 9a 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. If you wait any later than that and 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

In Zone 9a the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 9a and it will vary from year to year. Since half of the time in Zone 9a there is a last frost after February 15 be ready to cover your bok choi in the event of one of those late frosts.

USDA Zone Info for Zone 9a

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Zone 9a

You may be interested in your other planting guides for Zone 9a.