The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

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

Planting Calendar for Pennyroyal

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

Since pennyroyal do well in cold 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 Chaska 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 fully mature. You can get started a couple of weeks earlier by starting your pennyroyal indoors.

Last Frost Date

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

Since the USDA zone info for Chaska is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Chaska it frosts late in the year after May 15 so make sure that you are ready to protect your pennyroyal in the event of one of those late frosts.

USDA Zone Info for Chaska

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 Chaska

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