Before planting it is a good idea to find your USDA Zone info to estimate 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.

A way of getting a good idea when to plant spearmint is to examine the USDA zone info for Des Moines.

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 quite a bit earlier in the year because they are very cold tolerant.

The earliest that you can plant spearmint in Des Moines 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. Any later than that and your spearmint may not have a chance to really do well. 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 Des Moines. In the coldest months of winter you can expect an average low temperature of -15°F.

Remember that USDA zone info for Des Moines is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Des Moines you get a frost after April 15 so just be sure to be ready to protect your spearmint in the event of one of those late frosts.

USDA Zone Info for Des Moines

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Des Moines

You may be interested in your other planting guides for Des Moines.