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

By checking out the USDA zone info for Douglas it's possible to estimate when it's a good idea to plant napa cabbage.

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 a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant napa cabbage in Douglas 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. If you wait any later than that and your napa cabbage may not have a chance to fully mature. You can get started a few weeks earlier by starting your napa cabbage indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Douglas. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Douglas is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Douglas you get a frost after May 15 be ready to protect your napa cabbage in the event of a late frost.

USDA Zone Info for Douglas

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Douglas

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