One of the best tools that you have as gardeners to help us estimate 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.

In Mason City you can determine when it's the best time to plant pennyroyal by reviewing 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 can survive in a bit of cold which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Mason City 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. You can get started a couple of weeks earlier by starting your pennyroyal indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Mason City and it can change quite a bit from year to year. Since half of the time in Mason City 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 Mason City

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 Mason City

You may be interested in your other planting guides for Mason City.