One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when you can plant pennyroyal is to refer to the USDA zone info for Spencer.

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 a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

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

Last Frost Date

In Spencer the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Keep in mind that USDA zone info for Spencer is just an average and the actual date of last frost changes from year to year. Half of the time in Spencer there is a last frost after April 15 so always be ready to cover your pennyroyal if you have a late frost.

USDA Zone Info for Spencer

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 Spencer

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