One of the first steps you take when you are estimating 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.

In Bonne Terre you can determine when it's the best time to plant polygonums by referring to the USDA zone info.

Planting Calendar for Polygonums

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

It's probably a bad idea to plant polygonums until after the last frost has passed because they require warm weather.

The earliest that you can plant polygonums 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 polygonums and expect a good harvest is probably August. Any later than that and your polygonums may not have a chance to fully mature. If you are starting your polygonums indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Bonne Terre. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Bonne Terre is an average the actual date of last frost will vary from year to year. Since half of the time in Bonne Terre last frost occurs after April 15 be ready to cover your polygonums in the event of a surprise 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.