The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Riverside it's a good idea to figure out when it's possible to plant sunflowers.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Sunflowers do not do well in cold weather which means that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant sunflowers 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 sunflowers and expect a good harvest is probably August. If you wait any later than that and your sunflowers may not have a chance to fully mature. Starting your sunflowers indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Riverside the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Remember that USDA zone info for Riverside is just an average and the actual date of last frost changes from year to year. Since half of the time in Riverside you get a frost after April 15 be ready to cover your sunflowers 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.