One of the best tools that you have as gardeners to help us determine 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.

You can figure out when it's a good idea to plant pennyroyal in Bolingbrook by reviewing the USDA zone info.

Planting Calendar for Pennyroyal

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

Pennyroyal tend to make it in a bit of cold which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Bolingbrook 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 pennyroyal and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pennyroyal may not have a chance to grow to maturity. Starting your pennyroyal indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Bolingbrook. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Bolingbrook may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Bolingbrook you get a frost after April 15 so make sure that you are prepared to protect your pennyroyal if you have a surprise late frost.

USDA Zone Info for Bolingbrook

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 Bolingbrook

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