Before planting it is a good idea to find your USDA Zone info to determine your garden 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 estimate when it's a good idea to plant pennyroyal by using the USDA zone info for Slinger.

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 means that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant pennyroyal in Slinger 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 really do well. Starting your pennyroyal indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Slinger the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Slinger is just an average the actual date of last frost is different every year. Half of the time in Slinger it frosts late in the year after April 15 so make sure that you are ready to cover your pennyroyal if you have a surprise late frost.

USDA Zone Info for Slinger

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 Slinger

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