Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Merrill you can figure out when you can plant sweet potatos by checking out the USDA zone info.

Planting Calendar for Sweet Potatos

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

It's probably a bad idea to plant sweet potatos until after the last frost because they are not cold tolerant.

The earliest that you can plant sweet potatos in Merrill 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 fully mature. If you are starting your sweet potatos 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 May 15 in Merrill. In the coldest months of winter you should expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Merrill is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Merrill last frost occurs after May 15 so make sure that you are prepared to protect your sweet potatos in the event of one of those late frosts.

USDA Zone Info for Merrill

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 Merrill

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