The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Hibbing you should be able to estimate when it's the best time to plant polygonums.

Planting Calendar for Polygonums

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

You can not plant polygonums until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant polygonums in Hibbing 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 really do well. You can get started a couple of weeks earlier by starting your polygonums indoors.

Last Frost Date

The average date of last frost is May 15 in Hibbing. In the coldest months of winter you can expect an average low temperature of -35°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Hibbing and it changes from year to year. Half of the time in Hibbing it frosts late in the year after May 15 so just be sure to be ready to cover your polygonums in the event of one of those late frosts.

USDA Zone Info for Hibbing

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Hibbing

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