Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Rialto it's a good idea to figure out when you can plant peonies.

Planting Calendar for Peonies

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

You can plant peonies slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant peonies 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 peonies and expect a good harvest is probably September. If you wait any later than that and your peonies may not have a chance to fully mature. Starting your peonies indoors is a great way to get them started a couple of 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.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Rialto and it changes from year to year. Since half of the time in Rialto it frosts late in the year after January 31 be ready to cover your peonies in the event of a surprise 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.