Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 read to estimate when it's the best time to plant columbine.

Planting Calendar for Columbine

Frost tolerance for columbine:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since columbine are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant columbine in Bonne Terre is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant columbine and expect a good harvest is probably September. You probably don't want to wait any later than that or else your columbine may not have a chance to really do well. You can get started a little bit earlier by starting your columbine indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Bonne Terre. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Bonne Terre is not always accurate and the actual date of last frost changes from year to year. Half of the time in Bonne Terre it frosts late in the year after April 15 so always be ready to protect your columbine 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.