One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to estimate when to plant sweet potatos by using the USDA zone info for Thief River Falls.

Planting Calendar for Sweet Potatos

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

Since sweet potatos are not cold tolerant you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant sweet potatos in Thief River Falls 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 sweet potatos and expect a good harvest is probably August. Any later than that and your sweet potatos may not have a chance to really do well. Starting your sweet potatos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Thief River Falls. It might get as low as -35°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Thief River Falls is not always accurate and the actual date of last frost is different every year. Since half of the time in Thief River Falls last frost occurs after May 15 be ready to cover your sweet potatos in the event of a surprise late frost.

USDA Zone Info for Thief River Falls

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 Thief River Falls

You may be interested in your other planting guides for Thief River Falls.