The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's a good idea to plant napa valley fern is to use the USDA zone info for San Bernardino.

Planting Calendar for Napa Valley Fern

Frost tolerance for napa valley fern:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since napa valley fern require warm weather you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant napa valley fern in San Bernardino 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 valley fern and expect a good harvest is probably September. You probably don't want to wait any later than that or else your napa valley fern may not have a chance to fully mature. If you are starting your napa valley fern indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In San Bernardino the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for San Bernardino is not always accurate the actual date of last frost changes from year to year. Half of the time in San Bernardino it frosts late in the year after February 15 so always be ready to protect your napa valley fern in the event of a surprise late frost.

USDA Zone Info for San Bernardino

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 San Bernardino

You may be interested in your other planting guides for San Bernardino.