One of the best tools that you have as gardeners to help us figure out 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.

The earliest that you can plant bok choi in Duluth should be determined 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.

Bok Choi are moderately cold tolerant which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant bok choi in Duluth 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. You can get started a couple of weeks earlier by starting your bok choi indoors.

Last Frost Date

On average the last frost is on May 15 in Duluth. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Duluth is an average the actual date of last frost is different every year. Half of the time in Duluth you get a frost after May 15 so always be ready to protect your bok choi if you have a surprise late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Duluth

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