One of the first steps you take when you are making a decision about your gardening schedule is find your 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 USDA zone info for Green Bay should be used to estimate when it's a good idea to plant pennyroyal.

Planting Calendar for Pennyroyal

Frost tolerance for pennyroyal:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since pennyroyal are very cold tolerant you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant pennyroyal in Green Bay 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. Any later than that and your pennyroyal may not have a chance to grow to maturity. Starting your pennyroyal indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Green Bay. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Green Bay may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Green Bay you get a frost after April 15 be ready to cover your pennyroyal in the event of a late frost.

USDA Zone Info for Green Bay

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 Green Bay

You may be interested in your other planting guides for Green Bay.