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.

You will be able to figure out when it's the best time to plant pennyroyal by referring to the USDA zone info for Harrisburg.

Planting Calendar for Pennyroyal

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

You can plant pennyroyal earlier in the year because they are very cold tolerant.

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

Last Frost Date

In Harrisburg the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Always keep in mind that USDA zone info for Harrisburg is just an average and the actual date of last frost is different every year. Since half of the time in Harrisburg there is a last frost after April 15 be ready to protect your pennyroyal in the event of a surprise late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Harrisburg

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