Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant spearmint in Havre 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.

You can plant spearmint much earlier in the year because they are very cold tolerant.

The earliest that you can plant spearmint in Havre 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. If you are starting your spearmint indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Havre and it changes from year to year. Since half of the time in Havre you get surprised by a frost after May 15 be ready to cover your spearmint if you have 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.