Before planting it is a good idea to find your USDA Zone info to estimate 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.

It's possible to estimate when to plant tithonia by checking out the USDA zone info for Riverside.

Planting Calendar for Tithonia

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

It's probably not a good idea to plant tithonia until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant tithonia 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 tithonia and expect a good harvest is probably August. Any later than that and your tithonia may not have a chance to grow to maturity. Starting your tithonia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Riverside is an average the actual date of last frost changes from year to year. Half of the time in Riverside it frosts late in the year after April 15 so make sure that you are prepared to protect your tithonia if you have one of those late frosts.

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.