One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

The first opportunity to plant spearmint in Spearfish should be estimated by reviewing 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.

Spearmint do ok in cold weather which tells us that you can plant them much earlier in the year than more sensitive plants.

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

The last month that you can plant spearmint and expect a good harvest is probably September. If you wait any later than that and your spearmint may not have a chance to fully mature. You can get started a little bit earlier by starting your spearmint indoors.

Last Frost Date

On average the last frost is on April 15 in Spearfish. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that USDA zone info for Spearfish may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Spearfish you get a frost after April 15 so always be ready to cover your spearmint if you have a late frost.

USDA Zone Info for Spearfish

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Spearfish

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