The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant bok choi in Suisun City can be figured out by using 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 do well in a little bit of cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant bok choi in Suisun City 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. Any later than that and your bok choi may not have a chance to fully mature. Starting your bok choi indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Suisun City the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Suisun City and it can change quite a bit from year to year. Half of the time in Suisun City there is a last frost after February 15 so make sure that you are prepared to cover your bok choi if you have one of those late frosts.

USDA Zone Info for Suisun City

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 Suisun City

You may be interested in your other planting guides for Suisun City.