The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when it's possible to plant spearmint is to use the USDA zone info for Willmar.

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 a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant spearmint in Willmar 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. You probably don't want to wait any later than that or else your spearmint may not have a chance to really do well. 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

On average the last frost is on May 15 in Willmar. You can expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Willmar is not always accurate and the actual date of last frost is different every year. Since half of the time in Willmar you get a frost after May 15 be ready to protect your spearmint in the event of one of those late frosts.

USDA Zone Info for Willmar

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Willmar

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