One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's possible to plant pennyroyal in Viroqua by looking at 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 plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant pennyroyal in Viroqua is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant pennyroyal and expect a good harvest is probably August. If you wait any later than that and 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

In Viroqua the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

It's important to remember that USDA zone info for Viroqua is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Viroqua you get a frost after May 15 so make sure that you are prepared to cover your pennyroyal if you have one of those late frosts.

USDA Zone Info for Viroqua

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Viroqua

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