Before planting it is a good idea to find your USDA Zone info to determine your garden 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 looked at to estimate when it's possible to plant chervil.

Planting Calendar for Chervil

Frost tolerance for chervil:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Chervil do ok in moderate cold which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant chervil 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 chervil and expect a good harvest is probably September. If you wait any later than that and your chervil may not have a chance to fully mature. If you are starting your chervil indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Rialto. It might get as low as 30°F during the coldest months of winter.

Keep in mind that USDA zone info for Rialto is an average and the actual date of last frost will vary from year to year. Since half of the time in Rialto last frost occurs after January 31 be ready to cover your chervil if you have one of those late frosts.

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.