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.

You should be able to figure out when to plant bidens by referring to the USDA zone info for Vincennes.

Planting Calendar for Bidens

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

It's not a good idea to plant bidens until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant bidens 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 bidens and expect a good harvest is probably August. Any later than that and your bidens may not have a chance to really do well. Starting your bidens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Vincennes is just an average and the actual date of last frost is different every year. Half of the time in Vincennes last frost occurs after April 15 so just be sure to be ready to cover your bidens 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.