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.

A common way of getting a good idea when it's the best time to plant calliopsis is to consult the USDA zone info for Rialto.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You should not plant calliopsis until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant calliopsis 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 calliopsis and expect a good harvest is probably September. If you wait any later than that and your calliopsis may not have a chance to grow to maturity. You can get started a little bit earlier by starting your calliopsis indoors.

Last Frost Date

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

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Rialto and it changes from year to year. Half of the time in Rialto it frosts late in the year after January 31 so just be sure to be ready to protect your calliopsis 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.