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.

You should be able to figure out when you can plant napa cabbage by referring to the USDA zone info for Zone 9a.

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 can survive in cold weather which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant napa cabbage in Zone 9a 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. You probably don't want to wait any later than that or else 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

The average date of last frost is February 15 in Zone 9a. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 9a 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 9a you get a frost after February 15 so make sure that you are ready to protect your napa cabbage if you have one of those late frosts.

USDA Zone Info for Zone 9a

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Zone 9a

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