One of the first steps you take when you are determining 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.

A common way of figuring out when you can plant pennyroyal is to refer to the USDA zone info for Rockford.

Planting Calendar for Pennyroyal

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

Pennyroyal are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant pennyroyal in Rockford 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. You can get started a little bit earlier by starting your pennyroyal indoors.

Last Frost Date

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

Remember that USDA zone info for Rockford is just an average and the actual date of last frost is different every year. Since half of the time in Rockford it frosts late in the year after April 15 be ready to protect your pennyroyal in the event of one of those late frosts.

USDA Zone Info for Rockford

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 Rockford

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