The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant pennyroyal in Oak Ridge should be determined by looking at 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.

You can plant pennyroyal much earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant pennyroyal in Oak Ridge 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. You can get started a little bit earlier by starting your pennyroyal indoors.

Last Frost Date

On average the last frost is on April 15 in Oak Ridge. You should expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Oak Ridge is an average the actual date of last frost will vary from year to year. Half of the time in Oak Ridge it frosts late in the year after April 15 so be sure to be ready to cover your pennyroyal in the event of one of those late frosts.

USDA Zone Info for Oak Ridge

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 Oak Ridge

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