One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's the best time to plant coreopsis is to look at 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 moderate cold which means that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant coreopsis in Riverside 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 coreopsis and expect a good harvest is probably September. Any later than that and your coreopsis may not have a chance to really do well. Starting your coreopsis indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Riverside. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Riverside is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverside last frost occurs after April 15 be ready to protect your coreopsis if you have a surprise 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.