One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

The USDA zone info for Marshall can be read to determine when it's the best time to plant pennyroyal.

Planting Calendar for Pennyroyal

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

Pennyroyal are very cold tolerant which tells us that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant pennyroyal in Marshall 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 really do well. You can get started a little bit earlier by starting your pennyroyal indoors.

Last Frost Date

The average date of last frost is May 15 in Marshall. 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 Marshall and it can change quite a bit from year to year. Half of the time in Marshall last frost occurs after May 15 so make sure that you are prepared to cover your pennyroyal if you have a late frost.

USDA Zone Info for Marshall

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 Marshall

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