One of the first steps you take when you are determining your gardening schedule is find your 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 USDA zone info for Zone 9b can be used to figure out when it's the best time 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.

Napa cabbage tend to make it in pretty solid cold which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant napa cabbage in Zone 9b is January. However, you really should wait until February 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 October. If you wait any later than that and your napa cabbage may not have a chance to fully mature. You can get started a little bit earlier by starting your napa cabbage indoors.

Last Frost Date

In Zone 9b the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 9b may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 9b you get surprised by a frost after February 15 so just be sure to be ready to cover your napa cabbage in the event of a surprise late frost.

USDA Zone Info for Zone 9b

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Zone 9b

You may be interested in your other planting guides for Zone 9b.