One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Pierre you can figure out when it's the best time to plant polygonums by reviewing the USDA zone info.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Polygonums do not do well in cold weather which tells us that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant polygonums in Pierre is May. However, you really should wait until June 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. You can get started a few weeks earlier by starting your polygonums indoors.

Last Frost Date

The average date of last frost is May 15 in Pierre. In the coldest months of winter you can expect an average low temperature of -25°F.

Just be sure to remember that USDA zone info for Pierre is an average and the actual date of last frost will vary from year to year. Half of the time in Pierre you get surprised by a frost after May 15 so make sure that you are prepared to protect your polygonums in the event of one of those late frosts.

USDA Zone Info for Pierre

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Pierre

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