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

One way of estimating when it's possible to plant sweet potatos is to consult the USDA zone info for Missoula.

Planting Calendar for Sweet Potatos

Frost tolerance for sweet potatos:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably a bad idea to plant sweet potatos until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant sweet potatos in Missoula is April. However, you really should wait until May 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. If you wait any later than that and your sweet potatos may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sweet potatos indoors.

Last Frost Date

In Missoula the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Missoula 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 Missoula it frosts late in the year after April 15 so be sure to be ready to protect your sweet potatos in the event of a late frost.

USDA Zone Info for Missoula

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Missoula

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