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

You should be able to determine when it's possible to plant pennyroyal by looking at the USDA zone info for Wyoming.

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 earlier in the year because they are very cold tolerant.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Wyoming. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Wyoming is an average the actual date of last frost changes from year to year. Since half of the time in Wyoming you get surprised by a frost after April 15 be ready to protect your pennyroyal in the event of a late frost.

USDA Zone Info for Wyoming

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 Wyoming

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