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

You will be able to determine when to plant napa cabbage by referring to the USDA zone info for Grand Forks.

Planting Calendar for Napa cabbage

Frost tolerance for napa cabbage:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant napa cabbage earlier in the year because they are very cold tolerant.

The earliest that you can plant napa cabbage in Grand Forks 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 napa cabbage and expect a good harvest is probably August. Any later than that and your napa cabbage may not have a chance to really do well. Starting your napa cabbage indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Grand Forks. In the coldest months of winter you should expect an average low temperature of -30°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Grand Forks and it changes from year to year. Half of the time in Grand Forks last frost occurs after May 15 so be sure to be ready to cover your napa cabbage in the event of a late frost.

USDA Zone Info for Grand Forks

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 Grand Forks

You may be interested in your other planting guides for Grand Forks.