One of the first steps you take when you are getting a good idea 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 Sonora should be reffered to in order to estimate when it's a good idea to plant napa valley fern.

Planting Calendar for Napa Valley Fern

Frost tolerance for napa valley fern:	Not tolerant of frost.
When to plant:	After the last frost.

Napa Valley Fern are not cold tolerant which tells us that it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant napa valley fern in Sonora 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 Sonora the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 20°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Sonora and it can change quite a bit from year to year. Half of the time in Sonora you get surprised by a frost after February 15 so just be sure to be ready to cover your napa valley fern if you have a surprise late frost.

USDA Zone Info for Sonora

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 Sonora

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