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.

You should be able to figure out when it's possible to plant napa cabbage by using the USDA zone info for Columbia Falls.

Planting Calendar for Napa cabbage

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

Napa cabbage do well in cold which tells us that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant napa cabbage in Columbia Falls 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 napa cabbage and expect a good harvest is probably September. If you wait any later than that and your napa cabbage may not have a chance to grow to maturity. If you are starting your napa cabbage indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Columbia Falls. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Columbia Falls may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Columbia Falls you get a frost after April 15 so make sure that you are prepared to protect your napa cabbage in the event of one of those late frosts.

USDA Zone Info for Columbia Falls

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 Columbia Falls

You may be interested in your other planting guides for Columbia Falls.