Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to figure out when to plant spearmint by reviewing the USDA zone info for Waterloo.

Planting Calendar for Spearmint

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

Spearmint are very cold tolerant which means that you can plant them much earlier than other plants that might not handle the cold.

The earliest that you can plant spearmint in Waterloo 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. You probably don't want to wait any later than that or else your spearmint may not have a chance to really do well. Starting your spearmint indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Waterloo. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Waterloo is just an average the actual date of last frost is different every year. Since half of the time in Waterloo you get surprised by a frost after April 15 be ready to protect your spearmint if you have one of those late frosts.

USDA Zone Info for Waterloo

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 Waterloo

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