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.

You can figure out when to plant sweet potatos in Lewistown 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 has passed.

Since sweet potatos require warm weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sweet potatos in Lewistown 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. You probably don't want to wait any later than that or else your sweet potatos may not have a chance to fully mature. 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 Lewistown. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Lewistown may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Lewistown last frost occurs after May 15 be ready to protect your sweet potatos if you have a late frost.

USDA Zone Info for Lewistown

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 Lewistown

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