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

In Princeton you can determine when it's possible to plant pennyroyal by checking out 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 do well in cold which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant pennyroyal in Princeton 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. 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 Princeton. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Princeton is an average the actual date of last frost will vary from year to year. Since half of the time in Princeton you get a frost after April 15 be ready to cover your pennyroyal if you have one of those late frosts.

USDA Zone Info for Princeton

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 Princeton

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