Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's possible to plant coreopsis by using the USDA zone info for Riverside.

Planting Calendar for Coreopsis

Frost tolerance for coreopsis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Coreopsis do ok in a little bit of cold which means that you can plant them a bit earlier in the year than more sensitive plants.

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

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

Last Frost Date

The average date of last frost is February 15 in Riverside. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Riverside is an average the actual date of last frost will vary from year to year. Since half of the time in Riverside you get surprised by a frost after February 15 be ready to protect your coreopsis in the event of a late frost.

USDA Zone Info for Riverside

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Riverside

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