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.

The first chance to plant pennyroyal in Napoleon should be figured out 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 pretty solid cold which tells us that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant pennyroyal in Napoleon 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

The average date of last frost is April 15 in Napoleon. You can expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Napoleon and it can change quite a bit from year to year. Half of the time in Napoleon there is a last frost after April 15 so just be sure to be ready to protect your pennyroyal in the event of a late frost.

USDA Zone Info for Napoleon

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 Napoleon

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