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

The USDA zone info for Rialto can be used to figure out 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 all chance of frost has passed.

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

The earliest that you can plant napa valley fern in Rialto 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 valley fern and expect a good harvest is probably September. If you wait 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 little bit earlier.

Last Frost Date

On average the last frost is on January 31 in Rialto. You can expect an average low temperature of 30°F in the coldest months of winter.

Remember that USDA zone info for Rialto may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Rialto you get a frost after January 31 so make sure that you are ready to protect your napa valley fern in the event of a late frost.

USDA Zone Info for Rialto

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 Rialto

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