The USDA Zone info is a great tool for gardeners to help us estimate 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 Riverside should be reviewed to figure out when 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.

Bok Choi do ok in moderate cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant bok choi in Riverside 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. Any later than that and your bok choi may not have a chance to fully mature. You can get started a little bit earlier by starting your bok choi indoors.

Last Frost Date

In Riverside the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Riverside and it changes from year to year. Since half of the time in Riverside it frosts late in the year after April 15 be ready to cover your bok choi in the event of a late frost.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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