One of the first steps you take when you are figuring out 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.

One way of making a decision about when you can plant pennyroyal is to refer to the USDA zone info for North Liberty.

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 much earlier than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in North Liberty 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 fully mature. Starting your pennyroyal indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In North Liberty the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for North Liberty is just an average and the actual date of last frost is different every year. Since half of the time in North Liberty you get a frost after April 15 be ready to cover your pennyroyal if you have a late frost.

USDA Zone Info for North Liberty

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in North Liberty

You may be interested in your other planting guides for North Liberty.