Before planting it is a good idea to find your USDA Zone info to figure out 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 a good idea to figure out when it's a good idea to plant tithonia by referring to the USDA zone info for Riverdale.

Planting Calendar for Tithonia

Frost tolerance for tithonia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Tithonia are not cold tolerant which means that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant tithonia in Riverdale 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. If you wait any later than that and your tithonia may not have a chance to fully mature. You can get started a few weeks earlier by starting your tithonia indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Riverdale. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Riverdale is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Riverdale you get surprised by a frost after April 15 so always be ready to cover your tithonia in the event of a late frost.

USDA Zone Info for Riverdale

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 Riverdale

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