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.

A way of figuring out when it's possible to plant pennyroyal is to look at the USDA zone info for Holdrege.

Planting Calendar for Pennyroyal

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

Pennyroyal can survive in quite a bit of cold which means that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant pennyroyal in Holdrege 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 grow to maturity. If you are starting your pennyroyal indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Holdrege. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Holdrege is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Holdrege last frost occurs after April 15 be ready to cover your pennyroyal in the event of one of those late frosts.

USDA Zone Info for Holdrege

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 Holdrege

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