Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Vincennes you should be able to figure out when to plant tithonia.

Planting Calendar for Tithonia

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

Tithonia do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant tithonia in Vincennes 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. You probably don't want to wait any later than that or else your tithonia may not have a chance to fully mature. Starting your tithonia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Vincennes 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 Vincennes last frost occurs after April 15 so be sure to be ready to cover your tithonia if you have a late frost.

USDA Zone Info for Vincennes

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 Vincennes

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