Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to determine when you can plant bok choi by checking out the USDA zone info for Zone 5a.

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 bit earlier in the year than other frost tender plants.

The earliest that you can plant bok choi in Zone 5a 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 grow to maturity. If you are starting your bok choi indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Zone 5a. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Zone 5a is an average the actual date of last frost changes from year to year. Half of the time in Zone 5a 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 surprise late frost.

USDA Zone Info for Zone 5a

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Zone 5a

You may be interested in your other planting guides for Zone 5a.