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.

You should be able to figure out when it's the best time to plant bok choi by using the USDA zone info for Des Plaines.

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 a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant bok choi in Des Plaines 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. If you wait 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

The average date of last frost is April 15 in Des Plaines. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Des Plaines is just an average and the actual date of last frost is different every year. Half of the time in Des Plaines there is a last frost after April 15 so make sure that you are prepared to protect your bok choi in the event of a late frost.

USDA Zone Info for Des Plaines

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Des Plaines

You may be interested in your other planting guides for Des Plaines.