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.

It's possible to figure out when it's a good idea to plant spearmint by using the USDA zone info for Oak Brook.

Planting Calendar for Spearmint

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

Spearmint tend to make it in a bit of cold which means that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant spearmint in Oak Brook 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 fully mature. You can get started a little bit earlier by starting your spearmint indoors.

Last Frost Date

The average date of last frost is April 15 in Oak Brook. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Oak Brook is not always accurate the actual date of last frost is different every year. Since half of the time in Oak Brook you get surprised by a frost after April 15 be ready to cover your spearmint in the event of a late frost.

USDA Zone Info for Oak Brook

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 Oak Brook

You may be interested in your other planting guides for Oak Brook.