When to Plant Spearmint in Marengo, IL

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.

It's a good idea to determine when to plant spearmint by looking at the USDA zone info for Marengo.


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 earlier in the year because they do well in cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant spearmint
Possibly ok, but a risky time to plant spearmint
Probably not a good time to plant spearmint

The earliest that you can plant spearmint in Marengo 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. Starting your spearmint indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Marengo the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Marengo is an average and the actual date of last frost changes from year to year. Since half of the time in Marengo you get a frost after April 15 be ready to protect your spearmint if you have one of those late frosts.

USDA Zone Info for Marengo

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 Marengo

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