One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant napa cabbage in Portola Valley by referring to the USDA zone info.

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 means that you can start planting them much earlier than more sensitive plants.

The earliest that you can plant napa cabbage in Portola Valley 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. Any later than that and your napa cabbage may not have a chance to grow to maturity. Starting your napa cabbage indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Portola Valley. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Portola Valley and it is different every year. Half of the time in Portola Valley it frosts late in the year after January 31 so just be sure to be ready to cover your napa cabbage if you have a surprise late frost.

USDA Zone Info for Portola Valley

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°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 35°F.

Plants to Grow in Portola Valley

You may be interested in your other planting guides for Portola Valley.