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.

You can determine when it's possible to plant calliopsis in Riverside by using the USDA zone info.

Planting Calendar for Calliopsis

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

Calliopsis require warm weather which means that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant calliopsis in Riverside is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant calliopsis and expect a good harvest is probably August. Any later than that and your calliopsis may not have a chance to fully mature. You can get started a few weeks earlier by starting your calliopsis indoors.

Last Frost Date

On average the last frost is on April 15 in Riverside. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember that USDA zone info for Riverside is an average and the actual date of last frost changes from year to year. Half of the time in Riverside there is a last frost after April 15 so be sure to be ready to cover your calliopsis if you have a late frost.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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