Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Portola Valley you can determine when it's a good idea to plant bok choi by reviewing 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 moderately cold tolerant which tells us that you can start planting them earlier than other frost tender plants.

The earliest that you can plant bok choi in Portola Valley 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 grow to maturity. Starting your bok choi indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Portola Valley. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Portola Valley and it will vary from year to year. Half of the time in Portola Valley you get a frost after January 31 so make sure that you are ready to protect your bok choi if you have one of those late frosts.

USDA Zone Info for Portola Valley

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Portola Valley

You may be interested in your other planting guides for Portola Valley.