Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 Riverside should be read to figure out when it's possible 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 much earlier in the year because they do well in cold.

The earliest that you can plant napa cabbage in Riverside 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. Any later than that and your napa cabbage may not have a chance to really do well. You can get started a couple of weeks earlier by starting your napa cabbage indoors.

Last Frost Date

On average the last frost is on April 15 in Riverside. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Riverside may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverside it frosts late in the year after April 15 be ready to cover your napa cabbage in the event of one of those late frosts.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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