Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant sweet potatos by looking at the USDA zone info for Havre.

Planting Calendar for Sweet Potatos

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

Since sweet potatos require warm weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant sweet potatos in Havre 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. You can get started a few weeks earlier by starting your sweet potatos indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Havre. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Havre is an average the actual date of last frost changes from year to year. Half of the time in Havre there is a last frost after May 15 so make sure that you are ready to protect your sweet potatos in the event of a surprise late frost.

USDA Zone Info for Havre

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 Havre

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