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

In Lisle you can figure out when it's a good idea to plant bok choi by looking at 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.

You can plant bok choi just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant bok choi in Lisle 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 really do well. If you are starting your bok choi indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Lisle. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Lisle is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Lisle it frosts late in the year after April 15 so make sure that you are prepared to protect your bok choi if you have a surprise late frost.

USDA Zone Info for Lisle

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 Lisle

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