One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Bonne Terre can be reviewed to figure out when 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.

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

The earliest that you can plant sunflowers in Bonne Terre 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. Any later than that and your sunflowers may not have a chance to grow to maturity. Starting your sunflowers indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Bonne Terre the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Bonne Terre is not always accurate the actual date of last frost is different every year. Half of the time in Bonne Terre last frost occurs after April 15 so always be ready to protect your sunflowers if you have a late frost.

USDA Zone Info for Bonne Terre

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 Bonne Terre

You may be interested in your other planting guides for Bonne Terre.