The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant pennyroyal in Berwyn should be figured out 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 are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant pennyroyal in Berwyn 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 fully mature. Starting your pennyroyal indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Berwyn the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember that USDA zone info for Berwyn is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Berwyn there is a last frost after April 15 be ready to protect your pennyroyal if you have a late frost.

USDA Zone Info for Berwyn

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Berwyn

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