When to Plant Napa Valley Fern in San Ramon, CA

One of the first steps you take when you are figuring out 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 San Ramon can be read to determine when 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.

It's not a good idea to plant napa valley fern until after the last frost because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant napa valley fern
Possibly ok, but a risky time to plant napa valley fern
Probably not a good time to plant napa valley fern

The earliest that you can plant napa valley fern in San Ramon 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. Any later than that and your napa valley fern may not have a chance to really do well. 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 Ramon 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.

Just be sure to remember that USDA zone info for San Ramon is an average and the actual date of last frost will vary from year to year. Since half of the time in San Ramon it frosts late in the year after February 15 be ready to cover your napa valley fern if you have a late frost.

USDA Zone Info for San Ramon

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 Low25°F
Highest Expected Low30°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 Ramon

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