The USDA Zone info is a great tool for gardeners to help us determine 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.

In Zone 3a you can determine when you can plant bok choi by using 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.

Bok Choi are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant bok choi in Zone 3a is March. However, you really should wait until April 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 August. If you wait any later than that and 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

In Zone 3a the average date of last frost happens on May 15. It might get as low as -40°F during the coldest months of winter.

Since the USDA zone info for Zone 3a is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 3a there is a last frost after May 15 so make sure that you are prepared to protect your bok choi if you have a late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-40°F
Highest Expected Low	-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in your other planting guides for Zone 3a.