The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when you can plant polygonums is to refer to the USDA zone info for Moorhead.

Planting Calendar for Polygonums

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

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

The earliest that you can plant polygonums in Moorhead 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. If you wait 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 couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Moorhead. In the coldest months of winter you can expect an average low temperature of -30°F.

Just be sure to remember that USDA zone info for Moorhead is not always accurate and the actual date of last frost is different every year. Since half of the time in Moorhead last frost occurs after May 15 be ready to protect your polygonums if you have a late frost.

USDA Zone Info for Moorhead

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Moorhead

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