One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Riverside you can figure out when it's the best time to plant echinacea by looking at the USDA zone info.

Planting Calendar for Echinacea

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

Echinacea are barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

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

The last month that you can plant echinacea and expect a good harvest is probably August. You probably don't want to wait any later than that or else your echinacea may not have a chance to grow to maturity. You can get started a little bit earlier by starting your echinacea indoors.

Last Frost Date

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

Since the USDA zone info for Riverside is just an average the actual date of last frost changes from year to year. Since half of the time in Riverside it frosts late in the year after April 15 be ready to protect your echinacea in the event of 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.