The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when it's possible to plant pennyroyal in Walled Lake 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 are one of those plants that can tolerate quite a bit of cold weather which tells us that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Walled Lake 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. If you wait any later than that and your pennyroyal may not have a chance to fully mature. 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 Walled Lake. In the coldest months of winter you should expect an average low temperature of -10°F.

Just be sure to remember that USDA zone info for Walled Lake is not always accurate and the actual date of last frost changes from year to year. Half of the time in Walled Lake you get surprised by a frost after April 15 so be sure to be ready to cover your pennyroyal in the event of a late frost.

USDA Zone Info for Walled Lake

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Walled Lake

You may be interested in your other planting guides for Walled Lake.