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.

One way of determining when you can plant pennyroyal is to use the USDA zone info for Greenbrier.

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 quite a bit of cold which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant pennyroyal in Greenbrier 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 fully mature. If you are starting your pennyroyal indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Greenbrier the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Greenbrier and it is different every year. Half of the time in Greenbrier you get surprised by a frost after April 15 so just be sure to be ready to cover your pennyroyal in the event of a late frost.

USDA Zone Info for Greenbrier

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Greenbrier

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