Before planting it is a good idea to find your USDA Zone info to estimate your garden 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 De Pere can be figured out by reviewing 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 quite a bit of cold which means that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant pennyroyal in De Pere 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 grow to maturity. You can get started a few weeks earlier by starting your pennyroyal indoors.

Last Frost Date

The average date of last frost is April 15 in De Pere. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for De Pere is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in De Pere it frosts late in the year after April 15 so make sure that you are ready to cover your pennyroyal in the event of a surprise late frost.

USDA Zone Info for De Pere

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in De Pere

You may be interested in your other planting guides for De Pere.