One of the first steps you take when you are determining your gardening schedule is find your 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.

The USDA zone info for Urbana should be reviewed to figure out when you can 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 can survive in moderate cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bok choi in Urbana 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. You probably don't want to wait any later than that or else your bok choi may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your bok choi indoors.

Last Frost Date

The average date of last frost is April 15 in Urbana. 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 Urbana is not always accurate and the actual date of last frost is different every year. Half of the time in Urbana last frost occurs after April 15 so always be ready to protect your bok choi in the event of one of those late frosts.

USDA Zone Info for Urbana

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 Urbana

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