One of the first steps you take when you are estimating your gardening schedule is find your 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.

One way of estimating when you can plant spearmint is to examine the USDA zone info for Glendive.

Planting Calendar for Spearmint

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

Spearmint are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than other frost tender plants.

The earliest that you can plant spearmint in Glendive 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. If you wait 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

In Glendive the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

It's important to remember that USDA zone info for Glendive is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Glendive there is a last frost after May 15 so make sure that you are prepared to protect your spearmint in the event of one of those late frosts.

USDA Zone Info for Glendive

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 Glendive

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