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.

A common way of estimating when it's possible to plant pennyroyal is to check out the USDA zone info for Glen Ellyn.

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 one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Glen Ellyn 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. You probably don't want to wait any later than that or else your pennyroyal may not have a chance to fully mature. You can get started a few weeks earlier by starting your pennyroyal indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Glen Ellyn and it is different every year. Half of the time in Glen Ellyn you get a frost after April 15 so make sure that you are ready to cover your pennyroyal if you have a late frost.

USDA Zone Info for Glen Ellyn

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 Glen Ellyn

You may be interested in your other planting guides for Glen Ellyn.