The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when to plant pennyroyal is to consult the USDA zone info for Willmar.

Planting Calendar for Pennyroyal

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

Pennyroyal are one of those plants that can tolerate quite a bit of cold weather which means that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Willmar is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant pennyroyal and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pennyroyal may not have a chance to grow to maturity. You can get started a little bit earlier by starting your pennyroyal indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Willmar. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Willmar and it will vary from year to year. Half of the time in Willmar last frost occurs after May 15 so always be ready to protect your pennyroyal in the event of a late frost.

USDA Zone Info for Willmar

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Willmar

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