One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The USDA zone info for Hiawatha should be reviewed to figure out when it's the best time to plant pennyroyal.

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 quite a bit earlier in the year because they are very cold tolerant.

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

Last Frost Date

The average date of last frost is April 15 in Hiawatha. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Hiawatha is an average the actual date of last frost will vary from year to year. Since half of the time in Hiawatha you get surprised by a frost after April 15 be ready to protect your pennyroyal if you have one of those late frosts.

USDA Zone Info for Hiawatha

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Hiawatha

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