One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant spearmint in Miles City can be determined by referring to the USDA zone info.

Planting Calendar for Spearmint

Frost tolerance for spearmint:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since spearmint do well in cold you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant spearmint in Miles City is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant spearmint and expect a good harvest is probably August. Any later than that and your spearmint may not have a chance to fully mature. You can get started a few weeks earlier by starting your spearmint indoors.

Last Frost Date

The average date of last frost is May 15 in Miles City. In the coldest months of winter you should expect an average low temperature of -30°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Miles City and it changes from year to year. Half of the time in Miles City it frosts late in the year after May 15 so always be ready to cover your spearmint if you have a late frost.

USDA Zone Info for Miles City

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 Miles City

You may be interested in your other planting guides for Miles City.